18" Wheel help

OllieDemon45 said

I just placed my order with Dr. Diff so here we go.

I purchased the rear spring relocation kit along with the perches. That being said, what options do i have now for the rear as far as offsets?
It will be a stock 8.75 with drum brakes and BBP but with the springs moved in the 1/2".

Thanks

Click to expand...

So it's an A-body 8 3/4 with the 1/2" offset kit and BBP axles?

By the math it's about 1.15" less per side than what I run with my 68-70 B-body 8 3/4. I'm running 18x10's with a +38 offset, which is a 7" backspace. That would work out to an 18x10 +8 with an A-body 8 3/4 and BBP axles, pretty much no wiggle room on those with 295's. 18x9's with like a 275 and you could do more like +0 to +20. By the math you should end up with about 6.85" from wheel mounting surface to the springs, so if you figure 1/2" of tire overhang and a 1/2" of clearance your maximum backspace is like 5.85". With 18's that works ok, if you go to 15's you need to figure more tire overhang than that so say 5.5" max backspace and that may even be a bit generous.