TOY: What wheel backspacing do I need for a SAS

[Kendall Carlton <kcarlton@xxxxxxxxxxxxx>]

I am in the processing of collecting parts for my SAS on a 88 Xtra Cab.  I
currently have the stock aluminum SR5 7" wide wheels.  I am planning on
going with 35X12.50 BFG MT tires on an 8" rim.  I also have a set of
aftermarket steel 8" wide American Racing rims off another IFS truck that I
think are 4 or 4.25 inch backspacing.  My question is can I use these rims
on a solid axle or do I need new rims?  Is there any specific backspacing
that works better in this application?

Thanks
Kendall
Colorado Springs, Co