How wide are your 15" rims. If they are less than 9" wide run a 26x8. If you put a 26x10 tires on an 8" rim the car will be all over the place. I made that mistake once.
Yes I geuss I should have told you that. My wheels are 15x9. I have BFG drag radials on them now but I can't get it to hook at all with them since i put this new motor together.
I say go 8" all the way.. Untill your hitting like 600+ rwhp i think 10 is just a waste and its much harder on everything.
I went from 2.20 60' with my 17's with 315/35 nitto's to low 1.5's with my 8" MT's at like 15+ psi. And if i had more motor the 60's would have kept on dropping. They may not look as cool but they will get the job done with less problems.
8.5 inch is all you need I ran them in Street warrior when I was in that class and I ran 11 psi and launching the car at 5800-6000 rpm off a 2 step what a rush!