Dad's 1979 GMC Heavy Half Transformation

[Dads79GMC]

Well, thought I'd start a build thread after nearly eight years!!

First off, my Dad purchased this truck in 79 and I've always loved it. I never quite liked that it was a LWB, However, loved everything else about it, even the oyster/cream interior. Dad was a Korean and Vietnam War veteran who finally retired in 1990. He gave me the truck in 2001 after being diagnosed with cancer, which got the best of him later that year. At the time, I had no room for it in town so I sent the truck into hibernation out at my cousins farm where it sat until November 2006.

Upon my return from Operation Iraqi Freedom in November 2006, I brought the truck back from South Dakota, it had been sitting in the elements for six years. It was so infested with mice dropping etc, that I had to drive with the windows down all the way home, yes, in November. Couldn't believe it made it, but it did. I immediately took it down to the frame, began to collect parts, and there it sat.......fast forward.

Upon my return from Afghanistan in 2011, I kind of started in again. I continued to collect parts, had a few things blasted and powder coated (rear end, front end components, cross member etc) and also found a 1979 heavy half SWB rolling chassis on craigslist for $100........Again, the project sat on and off since then.

I figured the only way that I was going to get serious about this project, is if I start a build thread so that I can get the old...."any updates"....."any pictures"...etc. I'm depending on all of you to keep me on my toes. This site is truly outstanding and an inspiration. Be patient, I'm in my 30th year in the Army Nat'l Guard, the last 20 years on active duty, which keeps me very busy.....but I'll find the time and make progress.

I'm missing most of the earlier pics from 2006. I'll slowly bring you up-to-speed over the next few posts.

[Dads79GMC]

Back in 2007, I replaced the corners, inner corners, inner rockers, outer rockers, floor sections on both sides. I wish I had those pictures, just can't find them. I got an estimate to do the mentioned work back in the day, and at that time a few shops wanted well above 2K, so I decided to buy a MIG welder and have at it. I figured it out and save a couple thousand.

That's enough for now.

Mike

[Dads79GMC]

Most recently, I've been working on the frame and changing ratios in the rear. Installed the 2.5/4" drop, installed new leaf springs. LSx swap will begin in about a month.

Mike

[Dads79GMC]

More pics of current work and originals I just came across from 2006. I know how you all love pics.

[MTCK]

Cool truck and story. Looking forward to the build.

[Dads79GMC]

Finally put the rear end together. Swapped the 3.08 for 3.73. Removed the overload and one leaf on the HD springs in order to gain another inch of drop. It's finally rolling on an extra set of rallies and scab tires. Don't mind all the footprints on the frame, the kid was enjoying bouncing on the rear.

OK, so I go to the front of the frame, climb up on the frame and give it a bounce.........nothing happens? The only bounce I get is from the under inflated tires???? I know there should be at least a little give in the springs, but nothing, nothing at all!! Today I call the local spring company "Husky Springs" to ask a few questions. Yes, I understand that it's just a bare frame minus engine etc. Anyway, after taking some measurements, we determined that the springs I put in are rated at 1060 pounds each, verses the second coils springs they sell rated at 843 pounds!!!!! I guess my 170 pound body isn't going to put a bounce into these springs! Still, even 843 pounds springs seem excessive?

Needs thoughts from the experts. The springs are standard height. Thanks Mike

[y5mgisi]

Subscribed

[walkerb]

Nice truck and progress. THANK YOU for your service to this great country!

[Dads79GMC]

Originally Posted by walkerb

Nice truck and progress. THANK YOU for your service to this great country!

Thanks

[MTCK]

Is that per each spring or the pair? That does seem a bit high. Just for comparison tuff country's (leaf) HD 4" lift springs are 495 lbs / in. If your front axle weight is ~2,500 lbs and you have two springs at 1060 lbs / in. you won't even have 1.25" of compression.

[Dads79GMC]

Originally Posted by MTCK

Is that per each spring or the pair? That does seem a bit high. Just for comparison tuff country's (leaf) HD 4" lift springs are 495 lbs / in. If your front axle weight is ~2,500 lbs and you have two springs at 1060 lbs / in. you won't even have 1.25" of compression.

Per the vendor, that's per spring. I find it hard to believe. Mike

[brakenit]

You can't compare leaf spring rates to coil springs. A manufacturer's coil spring rates are from direct downward pressure. The a-arm has leverage on the spring, which will change the amount of compression for a given amount of weight when they're actually installed in a vehicle.

Your truck is pretty cool, I'd imagine a Heavy Half longbed with bucket seats and a white interior are fairly unique. It should be pretty nice when you're done, I'm sure your father would be proud.

[MTCK]

Originally Posted by brakenit

The a-arm has leverage on the spring

That makes sense. It'd be easy to figure the ratio measuring from the a-arm pivot to the spring and from the a-arm pivot to the wheel mounting surface.

[Dads79GMC]

Picked up my engine today! Harness and ECM re-worked, includes pedal etc. Need to find a 4L60E.

[IowaHooch]

Sweet truck! Cant wait to see its progress

[Dads79GMC]

Originally Posted by IowaHooch

Sweet truck! Cant wait to see its progress

Thanks my friend, be patient, I think It'll be a slow build. Mike

[bnoon]

Nice! If I see some work on that engine, it may motivate me to do my 5.3 swap in the future! Are you doing anything to the engine before it goes in? Cam swap in those engines are big horsepower, but so is boost... I can't wait until I retire so that I can have time for all of my hobbies. LOL!

[Dads79GMC]

I wish I was retired too. Work keeps me to busy. No cam. Thanks Mike

[tip]

Watching this one!

[Dads79GMC]

Gents, the Army is killing me. Got the message!!

[green72s]

I'm subscribed. My son and I have a '79 that we work on together so your story is very special. Keep up the good work. Thank you and your father for your service.

[77K10Silverado]

Sweet! Subscribed!

[Odaroloc]

Very cool!

[Dads79GMC]

Kind of back at it?

So, I'm un-smoothing the firewall that I smoothed 7.5 years ago. Yes, I changed my mind!!! Why.....I don't know? Prefer the look of the OE AC unit I suppose. I had a lot of rust in the cowl that really needed attention and it was better to do it now than when it went to $hi! down the road.......I couldn't ignore it any longer nor get to it without major surgery!!!!

Nothing is welded at this time. I have A LOT of cleaning up to do and fitting before I slowing spot-weld the pieces in. The rust you see is surface rust and ten times better than what was there before. Probably should have searched out another cab, just couldn't bring myself to do it!!!!

I'll post more this weekend as I slowly install.

Be easy on me, I'm no pro.

Mile

[y5mgisi]

Ambitious! Cool to see that done!