The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board > Squarebody Projects and Builds

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 07-03-2019, 01:05 PM   #1
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Big Blue

I am starting a thread here to document the combination of two trucks into one.

Truck #1 A blue and white 1975 GMC C35 Sierra Grande 2wd/1ton, 350/TH400 86k miles. Saved from being crushed at the junk yard.

Truck # 2 The Rat a 1977 GMC K20. 4x4 3/4 ton, 4.8 LS swapped (Comp X260 cam, ls6 valve springs, headers), turbo 350.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 07-03-2019, 01:14 PM   #2
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

The body on truck #1 is really solid for a 75 where I live but its 2wd.

Truck #2 is not solid in any way the bed is barely held on, cab supports are ready to crumble, frame is really rough behind the cab, hood is rusted and cracked by the hood latch, and one fender might be ok and the turbo 350 has 4 neutrals. Despite the bad its got some good parts in it.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 07-03-2019, 01:26 PM   #3
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

The goal is to combine the best stuff from each truck onto this CUCV frame. I've never attempted any project this large before, I've done alot of research but still have alot more to go.

I'm going to start with getting the frame rolling. I'm going to make a list here to keep things organized.

1. Verify Gear ratio's on all three axles. I'm hoping I can use the rear from the 2wd so I dont have to move spring perches and I can keep the big rear brakes. Blue has 4.10's Rat has 3.21's (I guess that's why it got so much better gas mileage!)

2. See if I can use the 2wd JB8 front calipers on the 10 bolt.

3. See if I can reuse the Rat's old ubolts. Yeah right!

4. Order ORD bolt in steering brace.
Attached Images
 

Last edited by Honest Bob; 07-03-2019 at 09:19 PM.
Honest Bob is offline   Reply With Quote
Old 07-16-2019, 10:06 PM   #4
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Upon disassembly I found out that the input shaft on the 205 is what broke. The gearing mixed with the larger diameter tires was most likely the culprit.

Here is a vido of the rat on the dyno making 270whp and 291wtq.
https://www.youtube.com/watch?v=UYXwG8lXc1Y

My brother in law helped me remove the trans and motor, there isnt a whole lot more I need to pull, just exhaust gas tank and other small misc items.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 08-30-2019, 12:36 PM   #5
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Some shots of the parts truck, you can see why it was a parts truck.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 08-30-2019, 12:43 PM   #6
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

The Rat is gone!

https://www.youtube.com/watch?v=aOkxCn0BqZM


Picked up a 10 Bolt off of the classifieds and started cleaning it up.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 08-30-2019, 12:45 PM   #7
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Had to replace the ball joints and u joints on the one side, the other side seemed to have been done already, we will see if that comes back to bite me later on.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 08-30-2019, 12:49 PM   #8
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Covered the gas tank in por15 along with the ORD steering braces.
Attached Images
    
Honest Bob is offline   Reply With Quote
Old 08-30-2019, 12:54 PM   #9
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Prepping the steering box. I hope to get the front axle and a temporary rear axle under the frame this weekend.
Attached Images
  
Honest Bob is offline   Reply With Quote
Old 09-27-2019, 01:38 PM   #10
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Steering box came out good, got the front axle under the frame.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 09-27-2019, 01:39 PM   #11
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Got the bed off without any issues.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 09-27-2019, 01:41 PM   #12
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Front end came off and motor was sold the same day I listed it.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 09-27-2019, 01:43 PM   #13
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Ubolts arrived from offroad design! More prep and painting of the sway bar, gas tank brackets and 14bolt.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 09-27-2019, 01:45 PM   #14
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Rolling frame!!!
Attached Images
 
Honest Bob is offline   Reply With Quote
Old 10-24-2019, 03:52 PM   #15
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Trans and motor are in! Frame is off the cab and I got the hole cut out for the bolt in cover I saved from the other truck.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 10-24-2019, 03:54 PM   #16
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Cut whole in the floor with a jigsaw and a metal blade. Worked great!
Attached Images
  
Honest Bob is offline   Reply With Quote
Old 10-26-2019, 11:07 AM   #17
Shifty One
Registered User
 
Shifty One's Avatar
 
Join Date: Dec 2014
Location: Tucson, AZ
Posts: 521
Re: Big Blue

I'm watching your good work!
Shifty One is offline   Reply With Quote
Old 10-26-2019, 11:54 AM   #18
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Quote:
Originally Posted by Shifty One View Post
I'm watching your good work!
Thanks I cant wait to drive this truck again.
Honest Bob is offline   Reply With Quote
Old 10-26-2019, 12:54 PM   #19
LT7A
Registered User
 
Join Date: Oct 2015
Location: PNW
Posts: 3,472
Re: Big Blue

Ambitious project! You are making strong efforts to keep the upper hand on corrosion in the future. Good work. I have a question. You mentioned 3.21 gears. I wasn't sure which differential you are referring to. Was it a 10 12 or 14 bolt?
LT7A is offline   Reply With Quote
Old 10-26-2019, 03:17 PM   #20
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Quote:
Originally Posted by LT7A View Post
Ambitious project! You are making strong efforts to keep the upper hand on corrosion in the future. Good work. I have a question. You mentioned 3.21 gears. I wasn't sure which differential you are referring to. Was it a 10 12 or 14 bolt?
Thanks! It was a matching 10 bolt and 14 bolt full floater. I sold them and went with 4:11's.
Honest Bob is offline   Reply With Quote
Old 10-29-2019, 08:47 PM   #21
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Got the cab on and the hole cut in the cab for the removable hump I saved from the other truck.

oh yeah and it runs!

https://www.youtube.com/watch?v=Dklt1IxL1vM
Attached Images
   
Honest Bob is offline   Reply With Quote
Old 10-30-2019, 07:55 AM   #22
Greenlee
Registered User
 
Greenlee's Avatar
 
Join Date: Jun 2004
Location: El Lago, TX
Posts: 1,668
Re: Big Blue

Nice work! The new body looks solid.
Greenlee is offline   Reply With Quote
Old 11-04-2019, 12:41 PM   #23
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Quote:
Originally Posted by Greenlee View Post
Nice work! The new body looks solid.
Thanks! Yeah the body is really solid for a 75 around here.
Honest Bob is offline   Reply With Quote
Old 11-12-2019, 01:15 PM   #24
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

Finished up the brake lines, and found out I have to modify the exhaust due to the 1 ton shocks being in different locations than the 3/4 ton.

The exhaust was a little loud on the other truck so I added some glasspacks to quiet it down. Hopefully that works.

Also cut a piece out of the spare rad support to patch up the area under the battery on the "better" one. Figured it was a good area to practice welding sheet metal before I have to do the inevitable to the kicker panels/inner rockers, outer rockers, and cab corners. I really need to get an argon tank.
Attached Images
     
Honest Bob is offline   Reply With Quote
Old 11-12-2019, 01:17 PM   #25
Honest Bob
Registered User
 
Honest Bob's Avatar
 
Join Date: Jan 2017
Location: Easton PA
Posts: 209
Re: Big Blue

I had the throttle body gasket the wrong way around causing a vacuum leak so its running a bit better now. The Fi-Tech ecu is still learning it just needs some time I think.

https://www.youtube.com/watch?v=x5Ds6xh0Jjo
Honest Bob is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:49 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com