My first square body and could use some help/advice
 

So I just purchased my first square body, it’s a*78 GMC Sierra Classic 1500 LWB pickup and I love it. I am going to be using it for daily driving and to tow my Harleys occasionally. After searching for almost a year I found the perfect truck for me and my needs. I look to the rear end and I count out 11 leafs in the leaf spring pack, Monroe Air Shocks, and ride assist airbags. I look upfront and it has the disc brakes, a sway bar, Rancho shocks, and all the bushings are look to be in good condition.

The suspension is REALLY stiff and there is a lot of hard bounce when I go over any small or big bump in the road. Thr truck starts to acts as a seesaw almost and i have to apply my brakes to come out of it. So I need to figure this out ASAP plus I want to lower it but I am think of only a 2.5/4 drop and sit it on 18’s or 20’s with a nice amount of sidewall on the tires. To obtain that drop I was thinking of replacing all the shocks then doing 2.5 drop spindles up front and just removing 2 or 3 of the leafs in the rear to get that desired drop in the rear but will keep the ride assist bags to help with any load I may trailer and also install a sway bar in the rear. However, I will take any and all input.

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Again, this is my first square body and I can use any and all input that you all have to offer up. Thanks in advance!

Re: My first square body and could use some help/advice
 

Sounds like a fine plan to me.

Re: My first square body and could use some help/advice
 

9 leafs!! My light 3/4 ton has 8. My 1/2 ton has 6 with the heavier suspension. Someone had tried to trun your poor 1/2 ton into a 1 ton, and as a result it has way too much spring and pobably not enough shock in the back. My bet is someone had a very heavy camper on your truck.
Take out some spring, do your drop, install new bushings in the rear springs, and throw those air shocks on craigslist and put some KYB's on it (so you can get the correct length after drop). Add a sway bar. Not sure if the air overloads will work with the drop, assuming they do, they don't hurt anything. If you're towing your bikes on a trailer they probably aren't needed.

Re: My first square body and could use some help/advice
 

I have a C20 and did shackles/hangers and pulled 3 leafs from the rear. Got me six inches lower. I didn't drive it that much before I pulled it apart but pulling those leafs made a world of a difference.

Re: My first square body and could use some help/advice
 

Agreed....

Take measurements before doing anything. Remove some leafs (leave the 1st 5 or 6). Re-measure & see how you like the ride. If you like it, drop the front according to your tastes.

Re: My first square body and could use some help/advice
 

When I used to work at a spring shop 1 leaf equals 2 inches depending on the arch. Check to see if the springs are arched unloaded or flat.

Re: My first square body and could use some help/advice
 

It'll drop an inch and a half or so just losing the thickness of 4 or 5 leaves I would think before the new arch even comes into play. I think I'd ditch every other one and start there. Or, just junkyard a newer known(sort of) 1/2 ton pack. I'd try to leave the airbags if you could