Over 25 Years Later, Finally My 71 C-10 Truck Build

[Low Elco]

Congrats on the anniversary!

[Ol Blue K20]

X3 on the congrats. Happy Anniversary!

[hgs_notes]

Last summer I had some problems with the motor swap, transmission, etc. but eventually got the truck back on the road. We had a harsher than normal winter (for MN, that's saying something) and really didn't drive it or do anything with it. Spring finally arrived sometime in late May. I drove it once or twice. Then in early June I went for a drive and was thinking that I usually had some plan for a repair or improvement every year and didn't have anything in mind for this year. Mainly because of the struggle last year. I felt it was better just to get some miles on it.

But then on the way home the engine stumbled a bit. And got progressively worse. Then died while going down the highway and I coasted into a parking area for a small cemetery along the road about 2 miles from home. Fuel pump growling and stopping. Welp, I guess I know what I'm doing. After a wait of 10 minutes or so the fuel pump cooled enough to stay running and I drove it home.

That was a new inline pump from FI Tech. There were reviews when I bought it that said the pumps had died prematurely but I put the pump right where my old one was and had no issues with it. Different pump, different results. I decided to upgrade the fuel delivery system with a new tank from a 90 blazer with the in tank pump sump and a new intank pump.

It sat for a month while I gathered parts and got other things done and waited for the weather to improve. The old tank came out without too much difficulty. I wish I could say the new one went in as easily.


The new tank with the newer sending unit. I used a walbro universal in-tank pump (GSS342 with install kit 400-791).


The problems started pretty quick. Turns out the fuel fill inlet on the new tank is a larger diameter, the vent line for the fill is also larger, the new sending unit has special threaded flares for the GM EFI throttle body system that don't really have standard fittings available (at least that I could find while in the middle of the install).

I checked at the parts store for fittings or lines and you can get sections of stock fuel line but it's expensive stuff and doesn't really help with the install because you would just cut it and use one end anyway to connect to the sending unit. So I went to the junkyard and we found a tank where the connected fittings weren't too severely corroded. I could have just cut the fittings off the sending unit and flared the tube (maybe) but the thing costs about $95 and if the level indication isn't working they are not likely to accept a hacked up unit in return. So I used the junkyard fuel line connectors with about 6" of the fuel line. Then I connected to new high pressure fuel line, the same as what I used for the install last year, using brass hose barb couplings.

I decided to keep the return fuel line from the corvette regulator/filter as it was, dumping back into the fuel fill hose so I didn't have to redo that section. It worked so why not. So on that connection on the sending unit I just plugged the attached junkyard hose.

The fuel filler hose was rednecky but should work. The outside diameter of the old hose was about the same as the diameter of the new tank fill tube. Which is about the same inside diameter as a radiator hose. Yes I know it's not rated for use with gas. What I did was use it as a coupler that just wraps around the 2 ends butted together. The radiator hose will see almost no contact with gas. If it fails I'll change it. I had to use what was available to me at the time. If it ever comes to that I'll weld a couple pieces of the correct diameter steel tube/pipe together to make an adapter.

The fuel fill vent line is about 5/8" compared to 1/2" of the old one. I was able to weld a 5/8" diameter fitting onto the steel tube used on the blazer fill vent line and a piece of 5/8" hose I had around.

The wiring wasn't really a problem other than I was short of the correct size butt connectors which meant another trip to the store. I'm 9 miles from town and 20 miles from any major big box stores. The wiring from the sending unit has a single connector for the fuel pump and gas level gage. I cut the connector off because those wires on the truck are on opposite frame rails and I don't have those connectors anyway. I did test that the pump spun before putting the tank in the truck. I had to extend the fuel pump wire a couple feet to reach the wire from the throttle body but that's all that was required. Connected the ground wire and was ready to install the tank.

The only hassle I had getting the new tank mounted was that I didn't realize the new tank was the larger one available. The GM 15A is about 10" deep. The newer style 14B is a 31 gallon tank and about 3" deeper. The straps didn't wrap around the tank and reach the cross brace. I dropped the tank and loosened the front end of the straps as far as I could and tried again. They just barely reached through enough to get the nuts on. But they were long enough, thankfully.


The new tank hangs down more and I'm not thrilled about that. It's about the same look as if you use the 69-72 blazer tank which is deeper but shorter front to back. The square body blazer tank is about 28"x29" so it can be flatter for the same volume. But I do like having the higher volume. I think the 15C tank would have been the same dimensions as my old tank (25 gallon) and had the pump sump because it was for the 87 blazer/suburban. Something to consider if you go this route. Also, this tank probably wouldn't fit well under a short bed truck. I think it can be done but you have to move a crossmember and I think the track bar gets in the way, so if you have a GMC with leaf springs in the rear it might work.

So it's back on the road! I would still like to get the dash pad fixed this summer because the cover peeled up on the passenger side. We'll see.

[Palf70Step]

Glad to hear you got that fixed. 31 gal is a nice capasity for cruising fer sure!

[Ol Blue K20]

Looks like it'll be a ways between fill ups

[Low Elco]

Glad it's back together!

[Dieselwrencher]

Nice new tank! I finally got around to putting a tank under the rear of my bed so I feel your pain man!

[hgs_notes]

Originally Posted by Palf70Step

Glad to hear you got that fixed. 31 gal is a nice capasity for cruising fer sure!

Now I need time to drive it! Going to the street machine summer nationals Saturday.

Originally Posted by Ol Blue K20

Looks like it'll be a ways between fill ups

The 350 gets worse mileage than my old 283. Haha

Originally Posted by Low Elco

Glad it's back together!

No one more than me!

Originally Posted by Dieselwrencher

Nice new tank! I finally got around to putting a tank under the rear of my bed so I feel your pain man!

A couple hour job turned into an all day affair. Come up to St Paul Saturday and bring your truck!

[hgs_notes]

I've wanted to bring my truck to the Street Machine Summer Nationals in St Paul for many years. This was the year it happened...

[Ol Blue K20]

Looks like fun!

[Palf70Step]

[Dieselwrencher]

Awesome, looks like fun! I can't take my truck anywhere right now. I have 1 turbo off and need to rebuild the other.

[Ol Blue K20]

Originally Posted by Dieselwrencher

Awesome, looks like fun! I can't take my truck anywhere right now. I have 1 turbo off and need to rebuild the other.

That sucks.......danged diesels and their turbos...

[Dieselwrencher]

Originally Posted by Ol Blue K20

That sucks.......danged diesels and their turbos...

I had one pushing oil for a while now. They're a pain to et to/off so I have been avoiding it. I didn't rebuild the big one when I put it on the truck so I guess it is what it is. It started pushing oil out the exhaust really bad at the end of June hauling my 5th wheel. Poor truck.

[Ol Blue K20]

Originally Posted by Dieselwrencher

I had one pushing oil for a while now. They're a pain to et to/off so I have been avoiding it. I didn't rebuild the big one when I put it on the truck so I guess it is what it is. It started pushing oil out the exhaust really bad at the end of June hauling my 5th wheel. Poor truck.

I guess your tailpipe literally is pumping out Prius repellent. ......

[hgs_notes]

My old truck may see fewer miles after this last weekend.


The wife sold her Cadillac last week so we could get her a Camaro. We started out just shopping for a basic car on the cheaper end. She said she didn't care if it was a V8 or 6 or a coupe or convertible. And if it's her car I'm not going to argue. Even the 6 cylinder cars have over 300 hp, so no biggie.

Then we saw a few that really looked good that were SS's and in the high teens for prices. Ok, no problem. And her brother has a 2011 2SS convertible that she said was her "dream car" so we checked to see if he wanted to sell. Not just out of the blue, he has made rumblings about selling it. But he decided to hold onto it for now. No problem, there are others like it available.

So now we are looking at cars in the low $20's. We got a nice down payment with the sale of her car and another car still up for sale. So now we are sniffing around cars from 2013-15 and I check on what the 6th generation cars are selling for. Surprisingly I found a few nice 2017 convertible SS cars for just a few thousand over what a comparable 2011 was at. Apparently the dealers are trying to get the last remaining used convertibles off the lots before fall and the new 2019's come out because we were finding some at the wholesale price.

We got a sweet deal on this 2017 1-SS and it's an amazing car. We both love it. The new 6.2 has 455 hp and pulls like a freight train. Rides nice, gets unbelievable gas mileage (almost 28 mpg on the trip home at 75 mph). And the new convertible top operation is really cool. Has a built in cover piece, no snap in parts or anything. Just push the button on the remote key fob and about 15 seconds later it's down and ready to go.

[Ol Blue K20]

Nice! She's happy

[Palf70Step]

Yep, Keep mama HAPPY.

[Dieselwrencher]

Awesome! Congrats for you both! I haven't been following the new cars much. What is the difference from the 1-SS, and 2-SS?

[hgs_notes]

Originally Posted by Dieselwrencher

Awesome! Congrats for you both! I haven't been following the new cars much. What is the difference from the 1-SS, and 2-SS?

The 2SS has more options like leather seats, navigation, heads up display, etc. The 1SS is pretty well optioned as well. Like any new car nowadays. We didn’t find any 2SS convertibles of this generation for under $30k.

[Dieselwrencher]

Originally Posted by hgs_notes

The 2SS has more options like leather seats, navigation, heads up display, etc. The 1SS is pretty well optioned as well. Like any new car nowadays. We didn’t find any 2SS convertibles of this generation for under $30k.

Ok, makes sense now. It's crazy how much some options rack up the price. Either way, nice car!

[hgs_notes]

Wow, 3 years since the last post. I guess I haven't been doing enough work on my truck. That's about to change. Last fall I was driving down the highway heading north and half way there the exhaust tone suddenly changed. Like it had a miss. At idle it sounded normal but give it a little load and throttle and yuck. So on a trailer and drag it home hoping I don't make it worse. I didn't really start trying to diagnose the problem until this summer. I was mainly working on the 79 crewcab.

Compression test was ok. Nothing obvious. Played with timing, checked spark on all cylinders, changed the cap and plugs, no change. Bought a leak down tester and checked it today. Not good. Could just be head gaskets but possibly something cracked. I've got 3 cylinders that are really bad and a couple that are marginal. Problems on both sides.

I have been collecting parts to build a 383 sbc. The local machinist had a set of used (not much) rods, pistons already balanced and ready for install. I talked to him about the crank I had, brought it in and had him balance the whole rotating assembly. I got a 4 bolt block that hasn't been bored. As long as it's not cracked or have a ton of bore taper it will be getting bored soon.

I would like to have a roller cam and maybe aluminum heads. I have a set of vortec heads ready to go but they are limited for valve lift unless we disassemble and cut the spring seats down, which might be what I do.

I've also got a 200-4R transmission to swap in but it needs to be gone through first. Direct swap for the TH350 and with a few upgrades it's plenty strong. I may end up swapping gears after. I went from 3.73 to a 3.08 since I didn't have OD. Will have to see how it performs. I don't race it so it's just a seat of the pants Dyno.

Hopefully ready to go next spring. My first love needs some attention.

[Low Elco]

Awwwwwyeah......

[hgs_notes]

Making some progress on the new engine. The block is bored and Shrode is getting the bearings to install the rotating assembly. I just ordered a pile of parts to finish the rest of it. I went with a set of Brodix IK200 heads. These are a good flowing aluminum as cast head so it will be perfect for the level of performance I'm aiming for, good choice for the higher compression with the flat tops (about 10:1) vs iron heads. I was also looking at some Promaxx 200 heads, they were my first choice because basically they are the same as the brodix heads but a little cheaper and with a better valve job (5 angle vs 3 angle), but due to shortages for everything the Brodix supposedly have a much earlier delivery date. I chose a Howards hydraulic roller cam, 272/278 duration and .525" lift which I also have to wait on, until early March I think, due to the lifters. The cam is in stock, can't get the lifters. Getting a Cloyes timing chain set, roller tip rockers, Melling oil pump, summit 6 qt oil pan with built in windage tray, summit version of an edelbrock performer air gap intake and some ARP head bolts.

https://www.summitracing.com/parts/bro-1021007
https://www.summitracing.com/parts/hrs-cl111145-10

Nothing too radical but it should have good vacuum, mild chop idle and really decent power curve. The computers estimate around 450 HP and 500 ft-lbs I believe. Should be a fun cruiser.

This engine will be beyond the capabilities of my existing FI Tech EFI at full tilt. It should work for everything I intend to do but I might need to step up to a bigger system. At least I have several other vehicles to swap this one onto, probably the plow truck. That would be awesome.

Now that the engine is pretty much settled I'll have to turn my attention to the transmission. I have a 200-4R from a Monte Carlo I want to use because it's a direct swap for the TH350. I don't know the condition of it so it needs to be gone through and should get a few upgrades so it can handle the torque of the 383. It's the same transmission GM used in the GNX so I know it can handle it if built right.

There is another distraction though and that's the long time waiting cobra kit car. I did some financial restructuring and found some money to get an engine for it, a 5.0 coyote, which I picked up Friday. I'm always looking for a bargain and the prices on these engines (used) have doubled in the last couple years so I got one from a 2014 F150 with supposedly a cracked head. I'm in the midst of a teardown on it to see what I got. If it's a cracked seat it can be repaired no problem. If it's in the aluminum not many machine shops will fix it and I'll need to find a head. The first gen coyote in the truck was only rated at 360 hp, but I'm sure I can improve that a bit. I'm looking at either upgrades to the current heads or finding a set of 2nd gen heads (bigger valves, more lift, heavier springs) to get me over 400 hp. That should be plenty for a 2300 lb car.

Still need to find a transmission for the cobra. I'm looking for a good used 5 or 6 speed. Hit me up if you got a line on one.

Pic for attention

[Palf70Step]

Glad to see ya making some headway on the truck. Nice little kit, the cobra.