Okay, so I have an 85 c10 that weighs 4,000 lbs.

Motor makes 462 hp. @ 5700 rpm
465 Ft. lbs. @ 4200 rpm.

I'm running a 3600 nitrous stall in a built turbo 400 trans.
4.10 Gears in a truck 10 bolt. eaton posi.

dead hook cut a 1.8 60 foot
& went 13.16 @ 99 mph

i shifted at 6200 rpm 1st to 2nd, and 6200 2nd to 3rd. And i think when i crossed the line i was right at about 5000 rpm.

The tire i am running now is a M/T e/t street 315/60/15 which is a 30/12.4/15

So my question is should i drop down to a:
28/10.5
28/11.5
29/10.5
29/11.5
Or something different?

my trap speed needs to be higher, i really want to break into the 12's.
i might be able to shave another 100 pounds out of the truck which will help.
and i need a little better tune on my carb. but i defiantly need a different tire. I gotta get my trap speed up and a little bit less tire to have to rotate.

So what are your opinions? and if i need to post this in a different part of this forum please let me know! Thanks!

 

Seems like a simple question, so here is what I think, 15" sounds good.