Home Forums Gear Hunting Trucks and Four-Wheel Drives Suspension lift for '77 GMC

Question for the board,

I've a '77 GMC 3/4 ton 4wd that I use for plowing, firewood, etc. Runs pretty good. I need to get more clearance between the homemade flatbed that is on it an the tires, also would like to get more ground clearance on the truck overall because I had to weld on the plow mount up front and as a result is lower and prone to catching stumps/rocks whatever. I just snagged some 35's off the net and plan on putting them on. My question is this: I would like to lift it just enough to clear tires (yes I know I'll have to trim the corners of the wheel wells up front, and I can put blocks twixt the frame and the flatbed) with chains. Additionally, it's a 40 year old truck and the springs, especially the 2-leaf front springs are tired. So to that end I am planning on a suspension lift, with new springs all the way around. Will 2" be enough, and by only going 2" I shouldn't need new brake lines, driveshaft, etc. correct?

Any input greatly appreciated, especially any kits you can recommend.

Thanks,

Jason

A lot of the guys on truck oriented forums say you'll save money and get a better product if you go directly to a shop that does spring work and just have them make you a set. That way you can tell them exactly what your needs are and they can build you exactly what you need. I'd say with a half ton it might ot be abad idea to have a slightly heavier sprung front than stock since you're plowing, a custom shop could take care of that instead of a one size fits all kit.

Other than that I don't have a recommendation as I installed what will hopefully be my last ever lift about 10 years ago.

So you shouldn't need new drivelines with the 2" lift. Brakes hoses probably not but if they are original, I'd replace them with slightly longer ones anyway.

2" may clear 35's - I know 2" lift will clear 33" tires. Best approach is to get the tires mounted and on the truck and see what, if anything, hits when you cycle the suspension.

Thanks gents. Looks like I can get Tuffcountry 2" or 3" for about a grand. Good thing is the tires are coming mounted on rims already, so like you said I can mount them and see how much clearance I'll need. Tough thing to guess though, as I'm sure those front springs are sagging lower than new stock would be. I wonder if a guy could get away with 3" without new drive lines?

2" and fender trimming ought to work, depending on rim offset.

Check the spring rates before you order - as I recall Tuff Country are pretty low spring rate, which makes for a nice ride but will sag in before too long with a plow mounted - I put a set of 3" springs and a 1" zero rate add-a-leaf on a 86 Chevy, and it cleared 36"s with a bit of trimming. Skyjacker seems like a nice balance of spring rate and are good quality, Superlift were terribly rough riding. This is going off of memory from 10-15 years ago when I was really into putting old Chevy pickups together.

thanks prairie goat. Did you have to do anything to the driveline or brake lines for the 3" do you remember?

Tuff country has 2 options for the 2", an easy ride and an HD that they recommend for plows. Figured I'd go with the stiffer ones.

Also, brake line replacement wouldn't be a bad idea. Should be good on drivelines. Make sure and get a raised steering arm or drag link to prevent steering issues.

I didn't have to do drivelines with the 3", and this was on a short-box. Did put on new brakelines, as the stock lines were pretty stretched out during articulation.

Didn't know about the heavy duty springs - think that would be the way to go for your application.

Thanks again. Eventually I'd like to put a crate engine with a little more ass, but for now she puts around pretty good as is. I love the old oil burning, no seatbelt having, speedo don't work, carbourated girl. just fun to drive old pickups. And I give not one whit when I hit branches etc on the overgrown FS roads.

Fully agree, those old pickups are great! I'd think with chains your tires ought to be about like 36s without.....nice thing is the chains might do their own fender trimming if they get too close

I had to trim some off the back side of the front fenders as well.

Also, the gurus for those old GM's are www.offroaddesign.com
They could help with about any question for the suspension on those outfits. I used one of their shackle flips on a different pickup, which turned out really well.

If your planning suspension work on that old girl,
I would get out you favorite penetrating oil and dribble it
on everything under there. Tonight. And tomorrow night.
unless you are going to use a hot wrench.

As said before u might want to before just buying a commercial kit call a spring shop and see what they can build u the packs for. Most of the commercially bought sets are kinda assuming your not gonna haul as much in it. They might even be able to re-arc your old pack and add a spring or 2 if your not wanting to go monster truck

It will cost a bit more but have Deaver make you custom springs for your application. They can build the springs to your vehicles specific weight and gear them more for towing, flex or ride. Custom springs will out perform any off the shelf in every way possible.

Larry over on Expedition Portal has these chevy/gmc trucks dialed in...

http://forum.expeditionportal.com/threads/56355-Larry-s-1978-K10?highlight=Larry

http://forum.expeditionportal.com/threads/69228-Project-“Polar-Bear”-1989-V2500-Suburban?highlight=Larry

Check out his build threads for ideas....

Thanks for the springs recommendations.

Damn huntsonora, I need to start playing the lottery more. My God the things I'd like to do to this truck! Ideas are dangerous. Those builds are awesome. I'm more of a shoestring budget, and it can only be down for the upgrades a very short window, as it has to be on hand and ready to go.

BGG, I hear you. The beautiful thing about those trucks is parts are everywhere and they're simple to wrench on. I know Larry likes the superlift softride springs. Not sure it's much help but best of luck!

Dang Drummond, you've cost me a lot of time looking over Larry's builds over there. That guy knows his way around a GM!

Better go 4 inches for 35 s

I ended up getting the 3" Tuff Country lift. Got the springs on, still working on 40 yo brake lines. Also discovered a leaky gas tank as well, so I 've got 2 of those to put on as well and now there is snow to plow and no damned truck!

I don't know how to post pics on here anymore, but so far I'm damned happy. Soft ride, much more so than I'd figured, especially up front. Hanging the plow on there doesn't hardly even make a dent in the springs. Front is noticeably higher than the back, looks a little off but I care not one whit. Man, I love this old oil leaking sob. Just fun to drive them, took it all the way into town today to fill up the tanks, rest of the winter she'll just be pushing snow around. I'll need to add a leaf or put the airbags back in it to haul any serious weight this summer though which is a bit of a bummer.

Now, I need to figure out how to get a crate motor and rebuild the tranny in it and it'll be $hit hot for me. With the taller tires she does 60 on the highway no problem, and while OD would be awesome (and necessary if I were to make it into a daily driver) I could absolutely live with the old 4 speed in it.