Total noob just got a '69 GMC.

[1969GMC]

Hello all,

I just picked up this '69 GMC truck. It runs and stops. My plans are to make a daily driver out of it and use it to haul miscellaneous junk and a jon boat. This truck will be mostly for short distance driving. In the long run I'd like to put some more serious work into this truck.







I know very little about these trucks, and what I do know is mostly from lurking this website. I have been building air-cooled VW's for most of my life (Bus guy,) including engines from stock to strokers. I don't have much experience working with water cooled engines, however. I am hoping that some of you could maybe tell me something about my truck. Please assume that I know nothing.

My short term goals are to make the truck mechanically sound in every way. I was told that the engine is a 350, and the transmission is a TH350. There are a few things on the engine that have me confused, so I figured that I'd ask about them here. I've taken photos of them.




I'm assuming that this is the thermostat housing. There is a stack of washers on one side, and a bolt that doesn't look like it fits on the other. In addition there's a bunch of blue colored goo (Hylomar, RTV?) at the area where it mates with the intake manifold (I also don't know what type of intake manifold I have.) It leaks, but very slowly. I want to take care of this, but I don't want to mess with it until I have the right parts and at least a clue about what to do (e.g. what to do if stripped out, etc.)

The other thing that I don't recognize is the distributor.


Anybody know what distributor this is, or how to identify it?


And here's a pic of the engine. Does everything look to be in order?

Sorry if I am not posting in the right section, or not following site etiquette. I am new here.

Thanks,
Andrew

[1969GMC]

Bumping my own thread.

I am ordering the shop manual for my truck, and I also need to get a good reference book for the motor/trans. Any suggestions?

Thanks.

[raull]

welcome to the board , my first car was a72 super beetle , engines are engines so if you did your own bug engines , these v8's will be a breese for you , a shop manual will definatly help specially with torque specs and timing issues and ect , , the distributor in your truck is a modern hie which has a build in coil and does not have points , god knows ive had my share of sanding down points on the side of the road with my bug !! lol , there are sections on this site for every aspect of your build , thats where i would post any specific questions you may have , all the guys here are great people willing to help , good luck with your build ,

[JRANGER]

Nice looking truck..Im a total noob too so i cant help....But good luck!

[KSWes]

Good Luck on the project! This site is the best, I can think of any random idea I might have to do on my truck and do a search and most likely someone else has already had the same idea and has done the leg work... The only problem is ideas mushroom and eventually you have a million things you want to do! Maybe that's not a problem. Keep on keepin' on...

[ctandc]

Originally Posted by 1969GMC

Hello all,

I just picked up this '69 GMC truck. It runs and stops. My plans are to make a daily driver out of it and use it to haul miscellaneous junk and a jon boat. This truck will be mostly for short distance driving. In the long run I'd like to put some more serious work into this truck.

I know very little about these trucks, and what I do know is mostly from lurking this website. I have been building air-cooled VW's for most of my life (Bus guy,) including engines from stock to strokers. I don't have much experience working with water cooled engines, however. I am hoping that some of you could maybe tell me something about my truck. Please assume that I know nothing.

Welcome

Well since you know how to build VW engines, you actually know a lot more than “nothing”. Small Block Chevy’s are EASY. If you feel fine with building stroker VDubs, I have a feeling your “tow rig” will be sporting a big cube SBC (Small block Chevy) stroker before too long.

Originally Posted by 1969GMC

My short term goals are to make the truck mechanically sound in every way. I was told that the engine is a 350, and the transmission is a TH350. There are a few things on the engine that have me confused, so I figured that I'd ask about them here. I've taken photos of them.




I'm assuming that this is the thermostat housing. There is a stack of washers on one side, and a bolt that doesn't look like it fits on the other. In addition there's a bunch of blue colored goo (Hylomar, RTV?) at the area where it mates with the intake manifold (I also don't know what type of intake manifold I have.) It leaks, but very slowly. I want to take care of this, but I don't want to mess with it until I have the right parts and at least a clue about what to do (e.g. what to do if stripped out, etc.)

Odds are you just have a bad case of POIAI Syndrome. (Previous Owner Is an Idiot).

Yes, thermostat housing. Aluminum intake, looks to be an Edelbrock Performer intake.

Odds are that the bolts aren’t stripped, they just didn’t have the right bolts, or they had a different thermostat housing on there originally which used taller bolts.

Just get a new pair of bolts. You can match the length you want from Home Depot or wherever you like to buy bolts from.

I would yank that thermo housing off and at minimum clean all the RTV out, and make sure it even has a gasket (it should) and it’s clean etc. Perfect time to go ahead and drain the coolant and backflush the system while you’re at it, since the truck is new to you.

Personally I haven’t had good luck with the cheap chrome thermostat housings, I could never get them to seal. You can normally pick up a stock one at a local parts house for cheap.

Originally Posted by 1969GMC

The other thing that I don't recognize is the distributor.

Looks to be an HEI (Electronic Ignition upgrade for the older vehicles) very common install in older vehicles. The coil is mounted in the distributor cap. From the color it looks to be an Accel distributor, or at least an Accel rotor. You can use a normal HEI cap and rotor. They aren’t year or model specific. You just tell them a “coil in cap” HEI distributor cap and rotor. You’ll have to pull the coil from yours and install it in the new cap, it’s straight forward once you look at both the old piece and the new piece.

Originally Posted by 1969GMC

And here's a pic of the engine. Does everything look to be in order?

Looks normal. A few things might be cobbled together, but it’s not a deal breaker by any means.

Nice old school valve covers though.

To verify it’s actually a 350 (every “modern” small block Chevy since ’69 or so seems to be called a ‘350’) just google ‘chevrolet v-8 casting and date codes and locations’ and look it up.

Good luck.

[Pop's C-10]

Also swap tha fuel filter out..these things will leak over time..

[KSWes]

Defintely looks like it's got some water leaking around the thermostat housing. If you're going to drain your antifreeze and backflush and do what was recommended above I would also replace the thermostat while you're at it, it's an inexpensive part and if you're going to all the other trouble I would do that also. You might be glad you did if you're going to rely on the truck for transportation.

[Lower]

Looks like it was a stock 6cyl truck, the motor perches are in the back holes, thats why your distributor is so close to the firewall. Its nothing to change just makes it tough to work on the rear of the motor.

[1969GMC]

Thanks to all of you for the information and the encouragement.

Tomorrow I will go pick up a thermostat, gasket, stock thermostat housing, and bolts that are the correct size to get that straight.

As for the distributor, does anybody know how to time it? Is it timed at full advance with the vacuum line disconnected, etc? I really need to get a book to familiarize myself with these motors. Is there a must have book for SBC's?

Also, with the fuel filter should I just do a direct replacement? I don't know where it's supposed to be (in the engine compartment?) I will probably replace the rubber fuel lines as well, just to be on the safe side.

I will check on the casting codes and see what I have (although I guess it's really impossible to know for sure without tearing it down and measuring parts.)

Motor perches is a new term to me, but I did notice them and that they can be reconfigured. Is there anything that I can do to give me more clearance back there? The distributor is close enough to the firewall that it touches occasionally from vibrations. I have not attempted to set the timing on it yet, so I don't know if there is enough room to do that yet. I am currently researching the VIN and associated numbers to see if I can decipher how the truck was originally delivered.

@raull
That Bug looks mean. Here's a picture of my daily driver Bus.


@ctandc
I am already looking forward to building my first SBC.

I'm also looking for a stock steering wheel (or something full sized at least.)

[KSWes]

A Chilton's manual would be a good idea and they're available at any part store or off the internet. http://www.lmctruck.com They have specific shop manuals and assembly manuals, and could be helpful in your process also. I bought the shop manual. Although to be honest once I found this site and with the use of youtube. I haven't opened the book for months.

When you set the timing you'll need a timing light and I'm pretty sure I set mine with the vaccum advance hose connected to the carb. You could also check Youtube on this just do a search for "HEI ingnition timing" and you'll probably find what you need. I think In the end I was about 10 degrees before top dead center. My truck is a stock motor (350) with stock cam etc. I have an edlebrock performorer carb that has a specific Vaccum advance port. Looks to me like you have a Holley and I'm not sure if it's the same. Good luck!

[1969GMC]

Thanks KSWes. I am assuming that I should set the valve lash before setting the timing, am I correct?

Also, I am now having a new issue. I'm currently searching previous posts to see if I can find an answer. Basically the truck wouldn't start the other day. The starter was not making any sound whatsoever, so I assumed it was an electrical issue and checked all of the wiring. The wiring was in place, but the PO had it run really close to the headers so I replaced it with new wiring. The truck started fine afterward, but here's where it gets weird (I am pretty novice with automatic transmissions, so this may be obvious to anybody who knows about them.)

The truck has been starting very strong on the first key every time. Today when doing some errands in the truck, I noticed that the starter would hesitate for a split second when I turned the key, then it would start right up. After 3 starts like this the starter just wouldn't turn the 4th time. Again, I double checked my wiring and waited in the cab for the headers to cool down enough to jump the starter with a screwdriver. While waiting in the cab I tried to start it a few more times to no avail, then I heard a click and saw the shift lever move slightly. After that it started right up like nothing had ever happened. The weird thing about this is that before the truck would start in all gears leading me to believe that it did not have a neutral safety switch installed. I drove the truck straight home, and after parking it started again 3 times without issue... then it locked up again.

Any ideas about what I should look at? Like I said I am researching this right now by looking at previous posts, but any advice would be appreciated.

Thanks.

[ctandc]

Starting issue could be heat soak from the headers.

The one thing to check as well, is the HEI setup you have installed.
Sometime the installer uses the original wire and not a new wire. HEI likes all 12 volts.

Do the Google search of this forum and find the multiple write ups regarding this subject.

First step is the verify what a previous owner may have done, or not done. Nature of the beast.

If it turns out TO BE a starter hot soak issue, just google remote solenoid (“Ford style”) conversion and go from there.

Can be done cheaply with over the counter parts. Great upgrade for using a remote starter too.

As for timing vs valve adjustment..just start from scratch.

Search for finding TDC on a 350.
Go from there.
Then setup the distributor.
Do the valve adjustment then to, it’s easy, just follow the correct order for the piston position.
Probably needs new valve cover gaskets as well, so it’s convenient.

I’d also have the alternator / battery tested (local parts store should have a mobile cart for that purpose) it might save you time down the road.

Wouldn’t hurt to tune it up. New rotor, cap, spark plugs, maybe check the condition of spark plug wires as well.

Verify your vaccum adance is hooked up correctly as well.Check for cracked hose too.

If you plan on a reliable driver, better to knock it out now, and not fix it as you go, when you should be driving it.

First thing any used vehicle I buy gets is a full tune up, oil change, air filter, pcv valve, check for leaks, replace gaskets as needed, valves / timing, full tune up, coolant change etc.

I’ve found out it’s easier to get it done and out of the way, KNOWING it’s squared away and done right.

Good luck.

[1969GMC]

Thanks ctandc... it turns out that the PO had bypassed the NSS, and not bothered to do a great job (the 2 purple wires were held together with blue painters tape. )

I will take the rest of your advice as far as the tune up. My plans were to get the coolant flushed, change oil, set valves/timing, replace thermostat/thermostat housing, replace all gaskets that I remove, new fuel filter/fuel lines, cap/rotor, plugs (wires look good.) I have already tested the battery and the alternator, as I have the tools for this at home. The only other thing I need to do is get the fuel gauge working. I haven't taken a look at it yet but it stays on empty. I will post my findings here when I figure it out. I am going to do all of the work on this myself, so it should be a learning experience. I need to get SAE sockets/wrenches too, as all of mine are metric.

Thanks again to all who've replied to my thread. You've all been a huge help.

[VA72C10]

Welcome from just a little south of you in VA...

Looks like a pretty solid truck overall. And you've gotten some good advice....to add to that I'd look into a metal fuel line or braided...the ethanol in today's gas eats the stock rubber lines...don't want raw fuel spilling out all over your hot engine

[KSWes]

Lots of good stuff there to work on. I never did adjust my valves when I set my timing mine was running smooth before I changed over to HEI ignition so I didn't worry about it, but that's a good idea in addition to all the other things CT mentioned. If you have oil leaks on top of the motor it's probably from old rotten cork valve cover gaskets. I certaily did on mine when I got it. I spent the extra $$ for some good thick rubber ones, and no more burning oil smell...

I had to replace the battery cable that runs along the frame rail up to the starter also and I think it's a poor design with how big the starters are and how close the manifold is to the starter. I zip tied the bajezus out of my (+) wire to keep it far enough away from the manifold to not cook it, and I still don't like the way it is. But once I got the wire right it hasn't given me any trouble since.

I'm sure you're starting to think you're going to have to spend a boat load to get the truck solid. I think I spent about 300 on basic parts initially when I bought my 70, but I know now that it's not going to leave me on the side of the road and know the motor inside and out now and it was a great part of getting to know my truck. And you'll have peace of mind knowing everything is sorted out. And about the transmision, I don't know much about them either other than a great shop in KC to have any major issues taken care of and the basics to check the fliud when it's been driven about 30 miles to make sure it's at the correct operating temp, and the shift linkage is very sloppy on these trucks. My linkage needs rebuilt or replaced one of these days. I'd say a neutral saftey switch is a pretty important part. And should be available at most parts stores.

I'd probably do a priority list and just check it off as you go. Here is how it would probably look for me.

1. Neutral Saftey Switch,
2. Starter Issues/wiring issues,
3. A 12V Switched Power Wire going to the HEI distributer, there are a couple of places on the fuse block to attach a wire.
4. Timing & Valve Adjustment/Gaskets
5. T-stat and Cooling issues (Although if it's getting hot I'd put this at the top)
6. Fuel Filter and fuel lines (Unless you're having flow issues)

Correct me if I'm wrong folks I'm not a pro or anything...

Sometimes the most obvious problems shouldn't be the priority, Sounds like your PO, didn't do you any favors, mine didn't either, but it's good for bonding with your new project... Keep us posted...

[1969GMC]

Well, I got some time to work on the truck today so I did the most needful things.

First off I did a much needed tune-up including cap/rotor replacement, plugs, air filter, new fuel filter, timing, and inspection of all hoses, etc. The truck's in decent shape other than the things that stood out, it seems. I also had a really bad sounding exhaust leak that I was able to remedy with a new manifold gasket (thankfully.) 2 of the bolts were missing from the passenger side header as well. I will do an oil change this weekend and possibly renew the gasket on the pan, though it's not leaking so I may skip this. One other thing that was bothering me was that the power steering pump was making a groaning sound and was hard to steer when not revving at higher RPM's, so I attempted to bleed the air out of it for 10 minutes or so (cocked the wheel back and forth maybe 35-40 times.) There is a very noticeable improvement, but it still feels like there is air in there. I would also like to tackle the valve adjustment, but I need to figure out whether I have solid or hydraulic lifters. I've read that you can tell what you have by looking for the retaining clips down at the bottoms of the pushrods (C shaped for solid, and square shaped for hydraulic if I'm not mistaken.) Is this true?

Apparently you were right ctandc, I was experiencing a heat soak issue with my starter. The NSS wiring was not helping any, but by the time I worked that out the solenoid surely had plenty of time to cool and the successful starting was only coincidence. The next day I found myself stranded once again, and after letting it sit for 20 minutes it started right up. I went and picked up a Ford style solenoid and installed it near the battery. So far so good. This is an easy job for anybody who is reluctant to do it, and it seems like cheap insurance. I got the solenoid at my FLAPS for $13.



The one thing that worried me most was the thermostat housing and all of the RTV seemingly holding it in place. I purchased a thermostat and gasket, but the parts store did not have the housing so I stuck with what I have. One bolt was secured into the original threads, and the other was literally held in place by the silicone. After I pulled the housing I saw a large (well over 1/2") hole with absolutely no threads. Why?!? I picked up a 3/8"-16 tap and a 5/16" drill bit and had at it. I basically drilled about 3/4" past the bottom of the large hole, and then tapped it to the stock size. This required the use of an extra long bolt (1.5") but it works now and is no longer leaking.
Here are some pics of the hole with the tap in it, and the before and after pics of the housing.

I don't even get how this happened.



Much better now.


Next on my list is to try and figure out the fuel gauge (doesn't work, stuck at empty) and figure out what type of lifters I have so I can adjust the valves. I may just pull the cover from the timing chain (sorry, I'm not sure what the piece is called) so I can see what cam is in there and get a cam card for it. There are also lots of small gremlins that I can't seem to remember at the moment that I will get to one by one.

Thanks again to all who've replied to my thread. This truck is a lot of fun and I am already meeting lots of great people just driving it around.

@VA72C10... Going to handle the fuel line when I check out the fuel gauge in the next few days, what's on there now looks pretty good. Do you know of any shows/swap meets in the area for Chevy's/GMC's?

[ctandc]

Originally Posted by 1969GMC

Well, I got some time to work on the truck today so I did the most needful things.

“needful”……….I like that.

Originally Posted by 1969GMC

I would also like to tackle the valve adjustment, but I need to figure out whether I have solid or hydraulic lifters. I've read that you can tell what you have by looking for the retaining clips down at the bottoms of the pushrods (C shaped for solid, and square shaped for hydraulic if I'm not mistaken.) Is this true?

Do you hear a bit of clacking at idle? What about a fast idle?
Solid lifters are normally pretty loud, except for solid roller lifters, and well I’m guessing you don’t have those. I’d assume you have hydraulic lifters, so just give the adjustment a try.

Originally Posted by 1969GMC

Apparently you were right ctandc,

Can I get you to call my wife and repeat that? Oh never mind she wouldn’t believe you anyway. LOL.

Originally Posted by 1969GMC

I was experiencing a heat soak issue with my starter. The NSS wiring was not helping any, but by the time I worked that out the solenoid surely had plenty of time to cool and the successful starting was only coincidence. The next day I found myself stranded once again, and after letting it sit for 20 minutes it started right up. I went and picked up a Ford style solenoid and installed it near the battery. So far so good. This is an easy job for anybody who is reluctant to do it, and it seems like cheap insurance. I got the solenoid at my FLAPS for $13.

Glad it worked out for you.

Originally Posted by 1969GMC

The one thing that worried me most was the thermostat housing and all of the RTV seemingly holding it in place. I purchased a thermostat and gasket, but the parts store did not have the housing so I stuck with what I have. One bolt was secured into the original threads, and the other was literally held in place by the silicone.

At least you had one bolt that was holding it on. I’ve seen worse.

Originally Posted by 1969GMC

After I pulled the housing I saw a large (well over 1/2") hole with absolutely no threads. Why?!? I picked up a 3/8"-16 tap and a 5/16" drill bit and had at it. I basically drilled about 3/4" past the bottom of the large hole, and then tapped it to the stock size. This required the use of an extra long bolt (1.5") but it works now and is no longer leaking.
Here are some pics of the hole with the tap in it, and the before and after pics of the housing.
I don't even get how this happened.

Previous owners can surprise you.

Originally Posted by 1969GMC

Next on my list is to try and figure out the fuel gauge (doesn't work, stuck at empty)

Go the easy way first. Pull the sender from the tank and check the wires, check for movement etc.

Originally Posted by 1969GMC

and figure out what type of lifters I have so I can adjust the valves. I may just pull the cover from the timing chain (sorry, I'm not sure what the piece is called) so I can see what cam is in there and get a cam card for it.

“Timing cover” and you’ll need to pull the harmonic balancer to get it off. I’d clean it up and see if you have any leaks.
Start with the casting codes and go from there. When you replace the valve cover gaskets, get the casting # off the heads as well.

Originally Posted by 1969GMC

There are also lots of small gremlins that I can't seem to remember at the moment that I will get to one by one.

Welcome to the club. It’s actually half the fun.

Originally Posted by 1969GMC

Thanks again to all who've replied to my thread. This truck is a lot of fun and I am already meeting lots of great people just driving it around.

It happens that way sometimes.

[KSWes]

Nice progress! Agree with CT&D PO's can surprise ya. I would bet it's probably several PO's responsible. Looks like you're workin' it out though!