1989 GMC extended cab long bed work truck: Lowering

[dusterbd13]

I've been looking around, and reading a bunch of old posts, etc.

I'm really intrigued by the 4/6 and 3/5 drops guys are running. looks like most guys are going with a pair of springs and spindles, and a flip kit in the rear.

now, i don't want you to think that I'm stupid on suspension design, etc. Ive got an 87 S10 that's dialed in for autocross and regularly goes hunting miatas, ive built a few open track cars, and am currently revising a torsion bar mopar for my new autocross.track toy. I'm pretty good overall with making something stick through the turns. My downfall is making it ride good. this full size is probably going to be my daily. crappy roads, debris, dirt roads, fields, towing, really bad driveways/ditches/curbs/speed bumps....
you get the idea. i want it to ride good (like it does now), handle reasonably well, and be a no brainer to drive, unlike my s10 that hits on everything. (and its only 3/5 ish)

heres my questions.
1. my truck is a 4.3 5 speed. will the smaller/lighter motor effect most of the coils for drop on these trucks? also, who makes the best riding coils for this application?
2. with the rear flip kit, will i need shocks? also, what will this do for payload/towing capacity? any problems do to a long bed?
3. with this long of a truck, is a 4/6 going to be drivable with all that I'm hoping for? i don't want to be smacking frame leaving the junkyard, or getting high centered on that nasty road hump at my in laws place again....
4. where is the cheapest place to get the setup?
5. will my stock wheels, brakes, and 235/75/15 tires fit and work well with this combo?i hate the rubbing on my s10 (but then again, the 245/50/16's weren't even supposed to fit....)

anything I'm not thinking of with this? all the components pass visual inspection. no severe dry rotting of the bushings, minimal play and anything. so i should be able to just get away with a drop kit and sway bars.

let me know what you think.
(and the reason I'm doing this to a long bed is that i got the truck instead of my last paycheck from the company i worked for for 5 years, who filed bankruptcy over the summer).

Michael

 

[BHBurban]

If you went 4/6, your ride wouldn't change much. The front would stiffen up slightly from the shorter 2" spring. The rear is basically unchanged because the axle is on top of the stock spring. load capacity is unchanged because of the stock spring (even with the required frame notch), but since the axle is on top of the pack, it will bottom faster. I would run helper bags in the rear for two reasons. to maintain the load capacity (pump up the bags when you are loaded so you don't bottom on the frame, or when towing) and since the wheelbase is so long, it will help in certain approach/departure angles.
Ride quality on these trucks with properly lowered suspensions is largely dependant on tire size/and style. 20"/22" performance rubberbands are going to ride like ****. Touring type tires (17"/18") from fullsize SUV's or cars will offer a more compliant ride.

Your stock 15's will work but you will have to trim a bit off of the lower conrtol arms. With a 4/6 on 15's run a 255/60, and with the long wheelbase, it will ride awesome.

 

[DRAGGIN95]

If you went 4/6, your ride wouldn't change much. The front would stiffen up slightly from the shorter 2" spring. The rear is basically unchanged because the axle is on top of the stock spring. load capacity is unchanged because of the stock spring (even with the required frame notch), but since the axle is on top of the pack, it will bottom faster. I would run helper bags in the rear for two reasons. to maintain the load capacity (pump up the bags when you are loaded so you don't bottom on the frame, or when towing) and since the wheelbase is so long, it will help in certain approach/departure angles.
Ride quality on these trucks with properly lowered suspensions is largely dependant on tire size/and style. 20"/22" performance rubberbands are going to ride like ****. Touring type tires (17"/18") from fullsize SUV's or cars will offer a more compliant ride.

Your stock 15's will work but you will have to trim a bit off of the lower conrtol arms. With a 4/6 on 15's run a 255/60, and with the long wheelbase, it will ride awesome.

Word!

 

[1990GMCSIERRA]

gona look like a boat,,curious to see how it tuens out tho

 

[BHBurban]

gona look like a boat,,curious to see how it tuens out tho

I've seen a few. Yeah, it's like a limo, but I like it. Because there is so much sheetmetal, they need substantial rubber underneath them. Personally, I'd go with 70 series tires to balance out the look.

 

[dusterbd13]

i lik the idea of long, low, comfortable, and slow. as well as job site-a-ble (is that a word? well, itll show up in google, so i guess it is). thats the reason im keeping the vynil interior and rubber flooring. as well as the somewhat crappy paint. dont want to have to worry about scratches and such.

do you think that my stock tires will clear with the 4/6? theyve git kess than a 1000 miles on them.
how about a 2/4? i cant seem to find the 3/5 that i had found a while back. just 2/4 and 4/6

also, any pictures of these trucks in longbed/ext cab lowered like this?

last question: after dropping, will i run into interferance with exhaust, driveshaft being too long, or rear axle hitting the bed? im just thinking of stuff ive had happen in the past on other stuff ive dropped.

Michael

 

[BHBurban]

In the front, stock tires would hit the tops of the wells on big dips.

3/5 usually involves drop leafs, But they reduce load capacity, and are sometimes soft and bouncy. Or, you could do a hanger/shackle kit and remove the overload leaf, but that makes it bouncy too (but I guess helper bags would eliminate that in both secnarios)

With a 4/6 you'd have to notch the bed crossmember above the axle for clearance.

 

[dusterbd13]

what about using a flip kit and a 1 inch lift shacke in the back? (do those even exist for these trucks?)

will i still hit on big dips at 3 inches front with my 235/75/15's?

 

[1badgmc]

will i still hit on big dips at 3 inches front with my 235/75/15's?

At 3" you'll be fine. My Suburban is at 3" with stock tires.

 

[DRAGGIN95]

Yeah I used to have some 1 in lift shackle's on my 95 they work well!