axle spring swap questions 88 sub to a 64 sub

[jonzcustomshop]

I am going to convert my 64 suburban 2wd to 4X4
It is not going to be a build for any kind of wheelin, just a 4X4 for winter transportation.

my donor(s) are a 88 3/4 ton suburban.
an 87 swb fleet 1/2 ton with a 4 inch lift kit.
and a 88 1/2 ton 2wd suburban.

I am only allowed to use the lift kit off the 87, the axles and frame are spoken for.

so off the 87 comes 4 shocks, steering arm, front springs and rear blocks.

off the 88 3/4 ton comes front & rear axle, brake booster , turbo 400 and transfer case, and all the assorted bracketry from the front of the frame.

so now I have 3 options at the rear, use the 3/4 ton springs and brackets, use the 1/2 ton 2wd suburban rear springs and brackets (6 leaf), or use the springs off the 87 1/2 ton fleet (5 leaf), and the brackets off either sub.+ the 4 inch blocks.

which would be the best rear option?

I am thinking of using the 2wd sub springs, thinking they are stronger than the pickup, and might work better with my early sub-(roof, seat and glass in the back)
I don't think I need to use the 3/4 rear springs, I am not going to tow anything, and the fronts are only rated 1/2 ton anyway...

2 other questions about the 88 sub... what is the lever connected to the center of the rear end that goes to the frame, and I unplugged 1 wire from the transmission -reverse light I hope? not some sort of electric lockup?
and I unplugged a dual wire from the transfer case... what does that one do?

[Walts_restoration]

http://67-72chevytrucks.com/vboard/s...d.php?t=523559

I need to either do a 55-57 or a 60-66 as my next project. Im getting tired of dropping money in squares. im wanting to build a unique 4x4 next go around.

[jonzcustomshop]

Thanks for that link, hadn't seen that build yet, and he is doing similar to me.

anyone have opinions on the rear spring question?

[Walts_restoration]

you want to use the sub spring rather than the 4x4 ones? 2wd and 4x4 should be the same length and interchangeable. I see no downfall to using them if they are in good shape.

[jonzcustomshop]

my thought was even though they are 2wd, they might be more suited since they are off a sub which has a lot more steel over the rear axle than the swb truck, and are going back on a sub. just wonder if there is a difference in design between the 2wd spring and 4wd spring.

[jonzcustomshop]

another thing I noticed today, the front (rear end) spring hanger is different on all 3!
2wd sub is pretty small, and hangs about 1/2 inch below frame.
3/4 sub is bigger and hangs a couple inches below the frame and has an extra support bracket under the frame rail.
the swb 4x4 has a massive bracket that hangs about 4 inches below the frame rail.
my dd 4x4 sub is similar to the 3/4 ton, and a couple blazers we have are similar to the 1/2 ton 2wd....

[jonzcustomshop]

kinda on the fence today.. 3/4 ton rear spring and brackets, or the 2wd sub spring and brackets...
so the 3/4 ton spring is on a 88 sub, going to a 64 sub, I wonder if it would be too harsh of a ride? I like the 3/4 ton's spring hangers better than the 2wd's. although the spring hangers on the 2wd sub look just about the same as the ones on my 63 k/10!

[ChiefRocka]

Why not set everything up, with the 1/2 ton springs...then you could run a 'bastard' pack to your liking (ride/weight carrying)

['63GENIII]

You could even run the 3/4 t springs out back and take a leaf or two out if the ride is too harsh. I would personally like to run the bigger, better braced hangers if I could. Aren't the 3/4 t springs longer also? If so, they may give a better ride in the first place. Alot of guys are swapping from the 1/2t (51") to the 3/4 t (56") springs for a better ride. Guys are even getting late model 1/2 ton springs (62") for an even better ride.

[padresag]

on the vintage of suburban(88) that you have I believe that the rear axle hump is not as high as it is on the newer 4 x 4 p/u. less of a body mount challenge.
ron

[padresag]

here is the pics that I said that I would get for you. this frt end came from a blazer and installed in a 65 GMC panel. as he already had rear leaf suspension, he just installed the riser blocks in the rear

By rondavid at 2012-07-16

By rondavid at 2012-07-16

By rondavid at 2012-07-16

By rondavid at 2012-07-16
ron