George...

[69gmcc10]

I couldn’t resist waiting for the engine to get done so I took it for a drive with the old clunky engine in it (the engine runs ok, but at idle it still has a thunk, I figured I cant hurt it any worse), I cant wait for my new engine!

I should have not thrown away that old broke and worn out muffler. I took it off because the guts of it were blown out (literally), it was in the way when I was doing the trailing arm conversion and I didn’t think it could be louder. I was wrong, George sounds like a tractor with a 2 pack a day problem.

Initially I bedded in the breaks by slowly breaking from 40 mph down to10 mph several times and the larger breaks and braded steel lines have firmed up the rear breaks and now most of the stopping comes from the back. It is a different experience on hard breaking because the nose doesn’t pitch down when you hammer the slow pedal, but it will stop in a hurry. I don’t know how much of it is to any certain thing larger brakes, steel lines or just new breaks?

The posi and the flipped trailing arms works real well together to get traction to the ground, it hooks up better than any truck I have driven. The Monroe sens-a-trac shocks are super smooth and with the no limit panhard bar the rear feels very under control. On a side note, and I don’t know how it worked out, my wheels are only half an inch from being in the center of the fender.

The only thing I don’t like about the truck is the stance and wheels it currently has. It sits 1” higher in the front right now (32.5” in the front 31.5” rear), because I haven’t cut ½ a coil off like I plan, but that will happen when I swap in the 72 front end from my parts truck next spring. The wheels and tires are the only 5 on 5 wheels I have and they came from the parts truck, I added the hub caps to class it up.

Next up is to get the exhaust plumbed with the old engine in so when I get to installing the fresh engine I can properly break it in.

[69gmcc10]

This is the reare bumper on my truck. I have seen a few similar to it on other 67-72 trucks, can anyone tell me about it? Does anyone know if it was from the factory, did dealerships install them, anything? Does it have value to anyone? If it does, someday I might try and get it to someone who would appreciate it, if not I am gonna cut the ends off. No I am not trying to sell it right now.

Any help would be appreciated. Thank you!

[69gmcc10]

picked up 5 of these off craigslist for $50!

They are 15x8, 1 is missing the gmc emblem on the cap and 1 more is falling off, any suggestions on what to do to to fix this problem? are replacement stickers avalable?

[Houch]

Nice score. Pretty sure you can get the emblems through LMC.
Posted via Mobile Device

[69gmcc10]

Originally Posted by Houch

Nice score. Pretty sure you can get the emblems through LMC.
Posted via Mobile Device

Thanks for the info I will give them a look and see what I find.

[69gmcc10]

I installed my new Lokar shifter linkage so I can keep that exhaust up and in the frame rails. The linkage looks good and with a little more adjusting it will be spot on with the indicator on the column.

[fakerwade]

Looking good!!!

[69gmcc10]

When I first bought this truck and started thinking of what I wanted it to end up like, one of the things I knew is that I didn’t want some crazy high horsepower engine that was impractical, but I did want the engine to be as efficient and reliable as it could be. That being said, the exhaust of a vehicle is a very common focal point for people to try and eek everything they can out of an engine, so I went looking for scientific proof and rational explanations on how to design and build an exhaust system.


In my researching for an exhaust I read a magazine article about no loss exhaust systems and found a computer program for $40 that calculates harmonics and pipe velocity based on engine specs, it factors almost everything and allows you to adjust the volumetric efficiency as needed. When I uploaded my engine parameters it gave me the following information. I selected short headers for 3 reasons, first they were thicker and heavier than the long tubes, second they wouldn’t stick below the frame rails and finally I wanted to try and bring the torque curve in earlier in the rpm range. The commuter program said that the primary tubes should be 1.5 inches in diameter converge into a 2.5 inch collector. From there the “collector” length needed to be 42 inches long where it emptied into open air or resonation chamber to get the optimal torque range from the engine. If I were to add an H-pipe it should be 21 inches down the collector pipe. I am not running an H-pipe because of space under the truck but dyno testing shows that some times it helps, sometime it doesn’t and it never hurts. I am using Dynomax super turbo mufflers to cut down on in cab drone and noise since the muffler is under the seat in the cab. After the muffler it really doesn’t make much difference as long as you have a large enough pipe to flow the volume of exhaust you need.

When I can I will get pictures up of the entire system, but this is all I have right now.

[69gmcc10]

Forgot to mention, ran the exhaust between the body and the trans cross member, through the trailing arm cross member along the trailingarm and out infront of the rear tires. The feet get warm with the exhaust runnign so close to the cab, so I will be investing in heat protection. any suggestions?

[67c10rustbuket]

George is coming along great! The rear suspension looks very nice. Impressive! I have seen other threads about your bumper, apparently they were aftermarket perhaps dealer installed. They allow the tail gate to drop all the way down for ease of loading hay and/or???? (goats )for farmers.

[69gmcc10]

Originally Posted by 67c10rustbuket

George is coming along great! The rear suspension looks very nice. Impressive! I have seen other threads about your bumper, apparently they were aftermarket perhaps dealer installed. They allow the tail gate to drop all the way down for ease of loading hay and/or???? (goats )for farmers.

I dont need to worry about loading goats in my truck, I dont live in eastern montana, thanks for the info.

Anyone have any reccamendations about keeping the floor of the cab cool?

[CC69Rat]

Lookin good man ..

[69gmcc10]

Originally Posted by CC69Rat

Lookin good man ..

thanks, it's not quite the meticulous pieces of art you work on, but I hope it will get me form a to b with a smile on my face!

[CC69Rat]

I think you may have me confused with someone else ..

[gringoloco]

Originally Posted by 69gmcc10

Thank you gringoloco, you have been a huge source of info on how to convert to trailing arms.

If I haven't said it already, you're welcome! This is an entertaining thread- you have a creative way of making the mundane interesting.

Originally Posted by 69gmcc10

...Anyone have any reccamendations about keeping the floor of the cab cool?

Check out http://www.lobucrod.com/. I used it on my truck--works awesome(ly). I would also suggest a radiant shield of some sort under the cab, attached to the piping.


Posted via Mobile Device

[69gmcc10]

Originally Posted by gringoloco

Check out http://www.lobucrod.com/. I used it on my truck--works awesome(ly). I would also suggest a radiant shield of some sort under the cab, attached to the piping.


Posted via Mobile Device

Thanks again! That insulation looks perfect, good price too! I was thinking about making shields out of some of the old licensce plates I have and attatching them to the pipe, now I need to get a little creative and make it happen.

[69gmcc10]

My neighbors L-O-V-E me again! Sat morning, with the help of my father, I took the dog house off the truck and placed it in the front yard where it is gonna stay for a week! The wife is not impressed with the lawn ornaments. I don’t know why, she liked my gnome! We started the process of installing the new engine by getting the old engine and trans out fast and before 1 we were replacing seals on the th400. Cleaning off the trans was one filthy job, there was about one inch of dirt, sand and rocks caked on top of it. In advance I picked up almost everything, but the water pump, p/s pump and fuel pump and when we went to pick them up during lunch we had to go to 3 different parts store and spent 2 hours running around. Then I had to run back to the parts shop because they gave me the larger center bore flywheel to a 2 piece main and not a 1 piece (the flywheel I wound up with is also weighted). Then we married the new engine and the th400 and slid it back in on new polly mounts (all of the mounts disintegrated when I pulled them out). Word to the wise, keep all of the motor mount bolts loose when installing it in the truck or you will have a large fight on your hands because the frame mount hole and engine wont line up (only took me 40 min to remember that!).

[69gmcc10]

While I was under the truck I took some pics of the exhaust her are the shorty headers, the exhaust going over the trans cross member, through the trailing arm cross member and along the trailing arm until it goes under the frame rail and out in front of the tire. I didnt really want to deal with going over the axle and out the rear. It has a little rumble at idle and a slight in-cab drone at low rpm acceleration but that is without any insulation in the cab at all.

[69gmcc10]

Last week involved 1hr a night mad dashes before dark to get parts back on the truck and the down time I had at work to track down the little parts that hold up the progress so I could get the front back on before the end of the last weekend and the weather turned. On Sat and Sun I got almost everything on the engine and the hood and fenders back on, and I am glad I did, because this is what I woke up to this Tuesday morning.

[69gmcc10]

The dipstick gave me interesting problems because the old dipstick was too short to get above the headers and the new one stuck out and forward awkwardly. So, In keeping with the recycling theme and to remove some of the ugly that comes in a newer truck I measured the difference in length of the two sticks from the full and add lines and cut the difference of the top end of the newer dipstick (it happened to be 12 inches). I must have done it right because when I added 4 quarts of oil and then checked the dipstick it was perfectly measuring “add” for that extra quart of zddp I needed to add. It does get in the way of the plug wire looms but not a big issue.

[69gmcc10]

Post

The idea for the engine bay is like the rest of the truck, subtle. I want it to look as much like an old truck as possible when the hood is popped, so I used the old v-belt system, original style pumps and I even painted my shiny Edelbrock intake black to match. One of the most complicated parts of the process was finding a power steering pump pulley. I had one, but it was bent and I couldn’t order a black original style from any auto parts shop in town (they had lots-o-chrome) but finally found a used one for $10, strait as an arrow! The other issue was the thermostat housing, the vortec heads don’t use the same ½”temp sender as older heads, so to work with the stock gauges the sender is in the intake and I am looking for a water neck that will go over or around the sender because it is in the way of the original (again lots-o-chrome options, not what I am lookin for). I think I found a water neck that goes around the sender just enough to clear, it’s a gm performance part for $6, but we will see.

For a great thread on how to properly align your pulleys, again take a look at one of Bruce’s thread v-belt pulley alignment 101: http://67-72chevytrucks.com/vboard/s...d.php?t=318240

[69gmcc10]

I think my truck is now polyurethaned out (not a word, but I don’t care)! I have not got the cab mounts on yet but the core support has black energy suspension mounts because I physically couldn’t bolt the old rubber up, there just wasn’t much there and the bolts were corroded. I like the black mounts from energy suspension because it has graphite in the poly and is supposed to cut down on squeaking (red don’t got no graphite, squeaky-squeaky!), regardless of graphite or not I always install poly with plenty of lube for extra protection (yes, I see the joke) from squeaks. So with the body mounts, sway bar mounts, trailing arm mounts, engine mounts, panhard bar and trans mission mount (should have bought the complete kit) I don’t think I need to worry about any sway from mounts or them braking down on me in the near future. Forgot, need to save for poly shock bushing!

[69gmcc10]

Sorry, I haven’t posted for a while on this, so here is the update. I did get the truck running within 3 weeks of starting the project and it would have been 2 weeks but I had a fuel leak on the cab side of the fuel pump where it screws in, so I bought and bent a new fuel line. My mechanic friend said I wouldn’t be able to do it, but I bought a pre flared 30” piece and showed him wrong! The truck started right up on the first try and then when I went to set the timing I noticed the balancer was wobbling badly so I had to find a new, used balancer and re-shim the pulley. I got that fixed and took it for a drive it developed a clacking I can only imagine is a sticky lifter because we reused most of the lifters, so now I am digging in to clean up the lifter. I also need to rebuild the carb and do some adjusting on the advance curve because there is a significant stumble on part throttle response…..it never ends!

[69gmcc10]

Quick side note, when I put sortie headers on the old engine I had some problems with the header and the plug wire on number 8 contacting each other, so much that I had to add a heat sleeve to cover the boot. To combat this and not use Accell header plugs I had heard a rumor that NGK plugs were shorter than other plugs by about 1/4". If you call NGK and point blank ask them if there plugs are slightly shorter they will respond with, "Our plugs are made to O.E. specifications, so no they are the same size as any other plug for that application." Obviously they don’t know there own product because they are shorter and gave me more room than the Autolite plugs I had before.

So, if you are looking to buy some wiggle room from your headers and don’t want to go Accell grab some NGK plugs.

[gdavis]

Originally Posted by 69gmcc10

I think my truck is now polyurethaned out (not a word, but I don’t care)! I have not got the cab mounts on yet but the core support has black energy suspension mounts because I physically couldn’t bolt the old rubber up, there just wasn’t much there and the bolts were corroded. I like the black mounts from energy suspension because it has graphite in the poly and is supposed to cut down on squeaking (red don’t got no graphite, squeaky-squeaky!), regardless of graphite or not I always install poly with plenty of lube for extra protection (yes, I see the joke) from squeaks. So with the body mounts, sway bar mounts, trailing arm mounts, engine mounts, panhard bar and trans mission mount (should have bought the complete kit) I don’t think I need to worry about any sway from mounts or them braking down on me in the near future. Forgot, need to save for poly shock bushing!

Well it was time to up grade on the mounts. u got your money worth on them.