2x4 to 4x4 conversion

[emuplayer66]

I have a 1975 c20 sub and a donor 1987 k20.

The c20 is sweet...little rust, bb, runs great, 14 bolt ff, cruise control even works! The K20 has 350tbi, 400 trans, (208 transfer case???), 14 bolt sf. The k20 has a 4 inch lift on 33's...I would like to get 6-7 inches on the c20 with room for 35s.

The c20 is a "trailering special" edition what gearing is in the rear? will it match the dana 44 gearing from the 87 k20?

question #1...is it worth it to try and do a conversion?

Whats the parts list? What is the level of difficulty? what will be the biggest challenge?

The c20 needs new tires and I figured why buy $800 worth of tires when I can buy some parts and get the nice 33s on it!

on a side note...My neighbor has some jeeps...he came by and gave me some 38.5x16.5 on some 8 lug steellies....that c20 would look sweet on them!!!

 

[Corey 78K5]

The c20 is a "trailering special" edition what gearing is in the rear? will it match the dana 44 gearing from the 87 k20?

No way for sure to say what gears are in the rearend on the C-20. Only way for sure is to pull the rear cover to find out for sure. If it is in fact an unmolested vehicle and still has the build codes in the glove box then you can trace it from there. It would be a "G" code. I thought I still had the codes bookmarked, but I can still find them.
The front axle on the 87 is a corporate 10 bolt not a Dana 44. Basically the same thing though.

question #1...is it worth it to try and do a conversion?

Sure if you really like the Sub and want it 4wd. I wouldn't do it unless it has a cherry body and good interior.

Whats the parts list? What is the level of difficulty? what will be the biggest challenge?

Floorboard panels, Spring hangers and shackles, cross members, 4x4 tranny with transfer case, drive shafts, 4x4 upper shock mounts. That's all that I can really think of for right now. I converted a 76 C-20 to a 4x4 5 years ago and I found it much easier to just swap the whole body over to a 74 K-20 frame with a complete running gear. I pretty much did it over a 3 day weekend. It beat the hell out of grinding rivets for a month. I just changed out the floorboard panels to clear the t-case and everything else was simple. Bolt down the body and hook up a few wires and vacuum. lines.
Your biggest challenge with using a 2wd frame is stripping all the 2wd stuff off and then stripping all the 4wd stuff of the donor truck and drilling a bunch of holes to get it to all fit, and swapping trannys. I would not recommend it myself unless you just can not find a rolling 4x4 Sub donor chassis.

 

[emuplayer66]

What do I need floor board panels for?

Would it be easier to swap the body and the BB? The donor already has a th400 with a 208 I think. The reason I like the c20 75 so much is because its all original in and out...I bought off of the original owner...plus its CA smog exempt!

 

[emuplayer66]

If I swapped the bodies....do you think I can use the vin from the body to register it? As I said before, I would like to keep the CA smog exemption...

 

[Corey 78K5]

What do I need floor board panels for?

To clear the transfer case, other wise the body wont sit down on the frame with out a body lift and you would still need to chop a hole in the floor. It's only the two pieces in the center hump. The one closer to the dash is bolted in and the smaller one to the rear is spot welded in. Both are easy to remove and grafted to the 2wd floorpan. You will need to cut out the area for them but that can be done with a cut off wheel or sawsall.

 

[Corey 78K5]

If I swapped the bodies....do you think I can use the vin from the body to register it? As I said before, I would like to keep the CA smog exemption...

One thing I didn't ask was if the K-20 was a Sub or pickup. Cause the frames are different. If it's a Sub frame then there should be no problem with swapping the body and engine over and keeping it registered as a 75. Unless you have the uncontrollable urge to go telling the DMV what you did. Other wise just walk in with your paper work as if it's a 2wd and pay your fees.

 

[emuplayer66]

yeah...its a 87 k20 sub! My ex neighbor does body swaps for a living...I wonder how much he would charge me???

Sometimes I think of selling the 75 c20 and using the money to hook up the 87 k20? I would have a 4x4 tow vehicle....plus how much gas would I save with the 350 tbi? The K20 is very similar to the ORD project suburban...

The 75 is my daily driver right now...I bought it because I wanted to convert into a big nasty 4x4 BB mudder...then I bought the 87 (running at the time) as a donor to convert the 75 to 4x4. I took the 87 on a joy ride and it quit shifting...lets just say I drove it like a $900 vehicle.

 

[howdiy]

To clear the transfer case, other wise the body wont sit down on the frame with out a body lift and you would still need to chop a hole in the floor. It's only the two pieces in the center hump. The one closer to the dash is bolted in and the smaller one to the rear is spot welded in. Both are easy to remove and grafted to the 2wd floorpan. You will need to cut out the area for them but that can be done with a cut off wheel or sawsall.

My transfer case cleared just fine on mine

 

[chevysmithz71]

ok. So why are some hitting and some not??

 

[Corey 78K5]

ok. So why are some hitting and some not??

Two answers. 1) Worn cab bushings. 2) Tranny/transfer case combo.
You can probably get away with clearing a 208 case, but a big 203 is gonna be tough to clear. GM did modify the floorboards for a reason. That is reason enough right there.

 

[howdiy]

He did have a truck though and I have a suburban.

Do suburban floors change from 4x4 to 2x4?