Found the answer to the rear end problem. On the S-10 the measurement is 54 1/2 inches outside of the hub to outside, and 48 inches from backing plate to backing plate. Blazers are two inches wider.
Best case scenario for me since mine is going to be a street sometimes strip truck is a 1995 to 2001.
(LB4-V6 TBI or L35 4.3 V6 CPI)
(M50 Man 5 SPD trans)
(GU6 3.42 gear ratio)
(G80 Positraction, Limited slip)
By the way those codes are the codes normally found in the glove box. The true 8.5 has two little square looking things on the bottom of the case looking from the rear of the vehicle. If you pop the cover and find 11/16th carrier bolts it's an 8.5. The smaller bolts are a 7.5.
Coil springs for the rear end started in 02, and they have the same options as leaf springs.
Here's the address;
http://www.performancetrucks.net/forums ... nd-513020/