My slicks are wasted and I am trying to figure out what slick height I should run at the track. 28" or 29".

I have a 1975 chevelle with a 468 BBC, 400 trans, 3,500 stall, 12 bolt with 4.11s. It has approximatly 500HP, and weights 4,100 lbs. I am currently running 11.98 @ 111 mph on a set of M/T 28 x 10.5 - 15. I shift at 5,800 and go through the lights at 6,100.

I am now adding a 150 shot of NOS and I know that is going to change a lot of things. So... do I stay with 28" or move up to 29"? I am thinking of getting a set of Goodyear 29 x 12 -15s. Goodyear seems to be the only manufacture that when it says 29", it is 29".

i would step up to the 29'',
based on nos usage you will rpm higher and may run out of gear before the end of the track.
taller tire will help that slightly and also give a slightly larger footprint on the ground for a little better traction........ :)

Nice! Thanks. I feel that same way, but Summit, M/T and Hoosier tell me to stay with 28s. I'm going 29s.