72 K30 Build

[JJorgensen52]

Nice!! That truck is going to have a killer stance.

[mjensen]

Good work Brett!!! Maybe when I'm dropping my truck off (possibly) to a buddy of mine in Centerville, I'll have to stop by and check this thing out in person.

[rgunlock]

Very good progress! That looked like a LOT of work to get a 4wd roller.

[DWilbur]

How thick is your rubber bushing under the cab in front and rear. I will check mine later.

[7dee2]

Originally Posted by JJorgensen52

I'm in the same spot right now on the '50 (well minus the T-case ), my tailhousing is pretty close to the floor and not so sure I'm happy about it.

I think you can be pretty close if there isn't much movement possible in the body/trans mounts. Rubber will flex more than poly and these parts are supposed to be some what stationary right?

Originally Posted by DWilbur

How thick is your rubber bushing under the cab in front and rear. I will check mine later.

Front cab mounts are 1" with 1/2" in shim material for a total of 1 1/2". Rear cab mounts are 2 5/8" with one 1/8" shim for a total 2 3/4" installed. They're black poly Energy Suspension 34107G for a 67-72 K20. In comparison I think they were the same height as the old C30 mounts except for the core support the new ones are a little bit thicker. Our new trans/tc mounts probably add a smig and the later trans/tc cross member may not be quite as deep as a K20 by a nats a**. All in all I'm thinking it's peachy!



From these angles I’ve got some déjà vu going on. Reminds me of when we mocked up our sheet metal on the donor 84 K35 Crew Cab chassis last winter (green cab). Difference is this time we got to bolt down the old RV cab (without the little hole in the back) and it’s not a limo anymore it’s probably a good 3’ shorter at least!

[7dee2]

With the cab/body on we need to fit a few things. Started by installed the tc shifter and nailed the factory position. The console also got fit for the last time prior to restore it’s the first time it was actually bolted to the floor.

[Dieselwrencher]

Great work! I've got a 72 C30 Longhorn to convert to a K30 for a board member soon. Too bad the body is nice and the owner may not want to remove it.

[7dee2]

Cool DW do you think you'll do a build thread? I'd like to see that!


Here's what's up with the trans shifter linkage. If you recall we covered up one of the original mounting holes with the shackle bracket on that side. Flipped the bracket around until it lined up and bolted it to the upper existing mounting hole, and wala! Looks like it’ll work just fine right there but we’ll test it with the rest of the column in later to make sure. Front drive line from the K35 looks perfect.

[7dee2]

Started a hydroboost conversion, wasn’t really sure we were going to do this but after giving it some thought it made sense. GM went to this system with the brakes we now have and I don't want any pedal pressure issues later, the donor truck stopped on a dime! Jim (JJorgensen52) did this conversion on one of our main inspiration trucks and he made it look easy http://67-72chevytrucks.com/vboard/s...d.php?t=631136 what a really great write up Jim, thanks! We’ve got the same core parts essentially as Jim did so our push rod length was the same (ours was marked 71217).

[JJorgensen52]

Originally Posted by 7dee2

Started a hydroboost conversion, wasn’t really sure we were going to do this but after giving it some thought it made sense. GM went to this system with the brakes we now have and I don't want any pedal pressure issues later, the donor truck stopped on a dime!

You won't regret it! With those big tires and wheels and a decent load, the hydroboost really gives you peace of mind.

Are you going to be using the stock big block remote reservoir steering pump? If so, you might want to look into a GM 26073040 or similar reservoir; they came in Astro/Safari/Express/Savanna vans with hydroboost and have dual return fittings, but they look pretty much identical to the stock unit, and they're made of welded steel so easy to add/modify a bracket to mount it where you want it.

[7dee2]

Yes that is the plan we'll use the stock big block remote reservoir steering pump with a tee in the return line. Our thinking is we'll go down the same road as you did with the steering box and plumbing easy peasy!


Here are some pics of our modified brake pedal prior to the final fitment. Going to wait until I've got the rebuilt HB in place to punch the hole and finish fitting this piece.

[DWilbur]

Do you think it would still work lengthening the rod and using the factor hole.

[JJorgensen52]

Originally Posted by DWilbur

Do you think it would still work lengthening the rod and using the factor hole.

You can do it that way, many folks do. When I did it (and I think what 7dee2 is after as well) I chose to modify the pedal so that the hydroboost was a 100% bolt on - that way, should I have to replace it later, I could just buy one off the shelf.

[7dee2]

Yep our thoughts exactly and now is a good time to bring this up, I really liked Jim's approach on his 72 GMC (4x conversion) build. The entire truck is built with either a '72 C3500 or a '87 Sierra V3500. All the service parts are one or the other and bolt on with no or very little modifications required.


Put a steering column in place and finished the HB mounting plate mods. Also tested the rest of the trans shift linkage and there’s no problems. Thought I would do a quick check on the fan shroud as the new core support bushings were thicker. Gets a little close with this 18” fan but it fits well enough no worries.

[JJorgensen52]

Originally Posted by 7dee2

Gets a little close with this 18” fan but it fits well enough no worries.

What, no clutch fan?? That is my single favorite mod to do on these trucks, makes them SOO much quieter at cruising speeds. My '72 sounded like a turboprop on the freeway

[7dee2]

I know, I know I've got lots of history (bad) with non clutch fans I could tell ya!

While waiting for some parts to arrive guess what day it is, hump day? No that was yesterday but if you guessed it’s tubing time you’d be correct.

What you see is a pile of (crap) C30 & K35 bits and pieces, let’s see what fits. Started right off with the K35 brake lines once we figured out which ones were them. Another member (could it be Jim?) posted that they fit pretty well and I was pleasantly surprised he was not kidding! I’d hoped perhaps the fronts might land were the frame alignment holes are and they do sweet! We will order new lines but wanted to make sure that using the K35 style brake lines was a good idea first.

We also have started looking at a parking brake solution as we will probably try and use the same vendor (inline tube) for both and combine the order if possible.

[First c10]

Hey Brett, look like your coming along nicely that thing is going to be a beast. Looks great. On my sons truck I put rear disc's so no off the shelf piece would fit easily. So I used the stock front e brake section and made a new intermediate and rear cables. I had them made by www.controlcables.com Ed miller is the guy I worked with. Him and I emailed pictures back and forth until we had a solution even down to the correct clevises. They are in Southern California with like 3 day turn around. I changed the routing from stock by running the cables to the driver side inboard of the frame. I can try and get another picture if you want. I did have to make the cross bracket (2 cables to 1) as I didn't have the room for most I found and didn't want to spend 50$ for a fancy anodized piece of metal.
Hope this helps.

[First c10]

I still need to brace the passenger side brake cable but I am waiting till the exhaust is installed.

[7dee2]

Thanks, I’ve really liked watching your chassis come together you guys are doing a great job. I am trying to make off the shelf work as much as possible but this one is going to get us. We could use a good pic of the front brake cable frame bracket don’t have one of those and will probably need to fab something up.

Our donor K35 setup does have the same 2 into one going forward which I like but has some extra bracketry that in our case makes the right side not engage as well as I think it should. Both rear cables have different ends on the front or intermediate cable side (right is threaded, left is not). So far I’m thinking stock 1972 front cable like you guys and then custom from there. Good chance we might be able to use a stock K35 right rear cable but we will see, going to think on this for now.


Here’s some new and rebuilt stuff that showed up.

[First c10]

Attached is a picture of the end of the from cable and its mount. This is a stock 70 k20 bracket. I had to turn it so that the front cable would be inline with the rear cables.

The tank is the same tank I have a 31 gallon one with internal high pressure pump. Is that what you have there? Minus the HP pump? It fit well just needed to lower the full tube.

[7dee2]

Thank you sir, yep it is the 31 gallon thought about the 40 but then decided 31 was a better fit for us, ha pun intended! I know that was dumb.

Talk about fit our rebuilt K35 box did not fit right off and needed a little clearance. First few pics it wouldn’t clear last few it fits like a glove.

[7dee2]

We needed a later steering coupler for the later steering box as it has a smaller 17 spline input. Mated right up to the old 72 column and its shiny is the good news. Bad news is I had one but gave it away on the column we sold earlier, oops!

Plumbing the hydroboost is pretty straight forward using the mated steering box. The return line from the box needed a 90 degree bend to clear the inner fender we also rolled the inner fender lip a little in that area.

[JJorgensen52]

Originally Posted by 7dee2

We needed a later steering coupler for the later steering box as it has a smaller 17 spline input. Mated right up to the old 72 column and its shiny is the good news. Bad news is I had one but gave it away on the column we sold earlier, oops!

If you want to do away with the rag joint, '97+ Jeep Cherokee (old square style) should have the right ends on it and they're plenty long

Good progress!!

[7dee2]

Thanks Jim but we’ll stick with the shiny part since we have it now.

Here are the pics of the rest of the HB plumbing. So to adapt the old pump we just needed to add a tee in the return line to get the fluid back to the reservoir. We also changed out the pressure fitting from the pump to the old style inverted flare to accommodate the old pump. Jim did recommend an alternative pump in this thread for those not wanting the tee in their plumbing. http://67-72chevytrucks.com/vboard/s...&postcount=373

[DWilbur]

Why did you use the old pump. My friends 1987 1 ton had factory HB system.