85 GMC Sierra Classic 1 Ton Crew Cab

[Matt Man]

sweeet.

[Mattman2010]

Well I got both of the fuel tanks on and got all of the fuel system hooked up. Was having trouble with idle so I went back and found some vacuum lines not hooked up so I plug some and hooked others up and it runs great!

Next thing will be changing out all of the fluids and putting the bed back on so that I can use this truck to haul another crew cab 1 ton home to get the 6.2 out of.

[1985-GMC]

Cool, good to hear that it runs great now!

[Mattman2010]

Im talking about the shock mounts. To solve the problem of the spring mounts I am taking all of the spring hangers off of the k20 frame and going to put them on the c30 frame.

[Mattman2010]

So the past few days I have been busy working on getting the 4x4 stuff off of the K20 frame so that I can mount it to the crew cab frame.

Front body mount/spring mount


All of the parts, Rear axle spring hangers, front axle spring hangers/body mounts, engine crossmember, ect.






Here is the corp 14 bolt I am putting in place of the Dana 70HD


Dana 70HD removed




Now I am going to start mocking up the stuff to make sure everything is going to fit, then I will tear it down and paint the stuff and install it for the final time.

[1985-GMC]

You've been busy! Save your 2wd steering box encase you ever want crossover steering.

[Mattman2010]

Yes I have, lots of using the cutting torch, angle grinder, and chisel and hammer. I am keeping my 2wd steering just for that, after I get this rear axle mocked up I am probably going to remove the rest of the body and the drive train. Then I can start on the front and then start getting things painted!

[1985-GMC]

Good deal!

[joe231]

nice work!
I can't wait for the 4x4 conversion

[1985-GMC]

Lookin good!

[Mattman2010]

Thanks guys, Cant wait to get it running. I just got a new air compressor hoping it will help with sandblasting parts and painting the truck when it comes time.

[my4by2]

This things gonna be sweet once you get it all done with a Cummins in it!

[Mattman2010]

Originally Posted by my4by2

This things gonna be sweet once you get it all done with a Cummins in it!

I wish I could afford a cummins, I am just going to swap in a 6.2L diesel in for now till I can get around to affording a cummins to stick into it.

[my4by2]

Here's a few pics of the truck I gave up to before starting my new project. Like I said, I was just getting to the point of going overboard with it - like tearing apart a 4k mile engine to basically turn it into a race car.... The Cummins was great though & loved it while I had it!

[Mattman2010]

If I could even afford a cummins, there wouldn't be any money left over to modify it haha

[Mattman2010]

Well today I got the cab removed, thought it was going to be harder to remove than it was but the tractor made it really easy. I removed the front suspension/engine crossmember and also got the front body mounts removed. I as going to try to get the front body mount/front spring mounts mounted but I found out that it is not a direct bolt on, I am going to have to figure out where to mount them.

cab setting on the ground


moving the frame back into the shop


front suspension removed


the difference between the 2wd core support mounts and the 4wd mounts, you probably cant tell but the bolt holes do not match up

[Mattman2010]

Thanks, p_rubottom your build is looking good as well!

[jltait]

All,
Yes the k30 frame is thicker, but I am sure it uses the same crossmembers. Put the crossmember up inside the frame flanges resting on the lower flange instead of hanging below the lower frame flange like it does on the k10/20. Because of the shape it will kick the crossmember up the same as the frame depth difference. Here is a link to a k30 showing how the crossmember sits. this makes up for the frame depth difference.

http://www.rustfreeclassics.com/imag...olution%5D.jpg

JLT

[Mattman2010]

JLT, I tried to do what you said and stick the cross member inbetween the frame rails. This did not work. It does not set flat on the frame rails.



I could put some kind of spacer to get it to set right, but in the end it would cause my transmission/transfercase to be to high.

I am just going to mount it to the bottom and run some 3/4" spacers between the transfercase mount and the bushings. This will allow me to be right in line with the stock mount for my carrier bearing. I will not be 4x4ing this truck hard at all so having the cross member that low will not effect anything.

[Mattman2010]

These are a few things I need to get done before I go about mounting the body.

• Remove Engine/transmission/trasnfercase
• Weld up some holes that I need to drill new ones through
• weld up brackets that where damaged when removed
• mount rear shocks
• mount front shocks
• rebuild the front axle (ball joints, ujoinst, brakes)
• replaced rear brakes
• Paint chassis and axles
• Get drive shafts shortened/lengthened

For the most part these are the big things I need to finish getting done before I paint the frame. I have forgotten some of the little things, and some things that I am sure I forgot to address. After the chassis is painted and everything is installed I am going to mount the body and drive it like so till I can find a new cab.

[jltait]

Mattman,
Hmmm, I was sure the crossmembers were the same. I have one from k20 and 1 from k30. I will need to take a look again.....Just had a thought...usually all these trucks (at least the k20's have spacers. The crossmember rides below the frame and the bolts go through a spacer that sits on top of the frame rail then through the frame rail and finally through the crossmember. ...maybe put them between the frame and crossmember so the spacers sit on the frame and the crossmember sits up on the spacers. should be 4 spacers, 1 for each bolt.
I will try to repost picture showing where I am thinking to put the spacer. I plan the same type of conversion but with a nv4500/np205 soon, so I have a vested interest in your success.

[Mattman2010]

JLT, that could work, but as I have stated before if I go to high my carrier bearing on the drive shaft will not mount into the stock location. If i where to use the spacers that would wind up making it to high.

The way you have showed the spacers are not where the bolts go into, I understand what you are trying to show me. The spacers are not very long and they need to reach pretty far up. So I think if you used spacers you would have to make new ones.

The blue line shows where the holes are, the red block shows how tall the spacers would need to be.

I hope you can understand what I am saying. I am getting some spacers, but I plan on removing my drive train tomorrow so I can finish up a few things before I paint the frame, so I wont be able to get pictures of how I am going to mount it.

NV4500/205 sounds like a good tranny/transfercase. I am just putting the truck together for now and then rebuilding it later when I can find a new cab. I might try to find a different transmission and run a 205, but for now i am going with the th400/208.

[jltait]

Mattman,
I did a little research that I hope helps you. First 4 pic's are a double hump crossmember that I picked up for my truck when I do the nv4500/np205/4x4 conversion on my R30 ('87 2wd dually). This is from a '85 k30 dually that had an np205/sm465 4 speed, It slides right into the frame and sits nice and flat and appears to have the mounting position correct for the desired driveline angle. Next 4 are a mid 80's single hump, again it sits nice in the frame and appears to have the same mount height for correct driveline angle. Kind of hard to tell though 'cause I had to put it backward to clear the exhaust which is on the driver side on my R30. The last 3 pictures are of the crossmember in my current running (barely) plow truck It has a th700r4 and np208 transfer case and I do not think the tranny/tcase have ever been pulled from this truck. Note the mouting position and that it appears to be Identical to the double hump crossmember in the first series of pictures..

I had another truck previously that had a np205/th400 and it too had the doublehump crossmember. I think GM may have commonised the crossmember design in the mid '80's that may have been more tranny/tcase specific previously. I am thinking if you pick up a Doublehump from a mid 80's truck as shown that it should work for you.

[jltait]

Single Hump Pictures...

[jltait]

k20- th700/np208 doublehump crossmember