I agree with going to a bias with a standard trans.
You can make the radials work, but you are going to need some sort of clutch management, and a lot of
suspension tuning.
And, since you are going racing, once a radial looses traction, they are done, you run is over, they do not recover well, whereas the bias is less likely to break in the first place, and when they do, they still put the power down while spinning... and they recover well to boot with a slight lift and back to the rug.
Looks like you have a shift point up over 7000rpms, I would stick with the 26" tire, have the car done at 1000'-1100' and let it hang its tongue out for the finish. Kinda scary with the stock block (if you believe all the internet folk lore, and I know yours has been frozen), but, I think that's how it'll run it's hardest.
I have not looked at bias tires for over a year now, but I went with the ET Street R... couple guys over on the "fence" switched from Hoosier QTP's are were glad they did.
You are only making 10tq more than I, and was was letting it rip from 6000rpm (4.56's with a 2.95 1st gear) on a marginal track and it was pretty consistent, even though they were rolling over 10-20 feet out. Never quite got it all figured out but was going 1.62's, spinning, on a bad track. My drag radials would simply blow off (2.3-2.6 60's) at the same track at anything over 3500, and anything below that they would hook and bog (1.9-2.0 60's). When they did blow off, no amount of easing up would let them recover, it was full off the gas and ease into 2nd. Hitting it hard again (1st or 2nd) would just lite them off again... grab 2nd and walk it out.
Razor's edge those DR's.
Bla bla bla... sorry for the long post, just sharing my experience.