I have a set of Nitto 555R 275/50/15's that were on the car when I got it. They measure 25" tall With the old motor I tached out at 5100 rpm at the end of the quarter. Now a good converter which I didn't have at the time would change this with a good couple.
I went to a Mickey Thompson 28x12x15 because Mickey's in the past measure what they say they will. These tires worked on my 10" rims but I had rubbing issues with no air in the bags. They had a true 12" section width and a 10" tread width.
What I really needed was a tire that was 27" tall 11" section width and a 9" tread width for the proper clearance. I run a 10" rim.
Knowing that Nitto tires come in a little smaller than a standard 275/60/15 like the Mickey Thompson DR a lot of guys run on this forum I took a chance and ordered them.
They measure in at 27" tall 11" section width and 9" tread and fit perfect. No rubbing with zero air in the bags and that's hitting dips in the freeway at 70 mph.
I know the nitto's won't hook like the MT DR's but I don't care because I'll run slicks at the track. I just wanted a tire that would grip decent on the street and last a while. I had MT 275/60/15 DR's on the Cuda years ago when they first came out and I hated them on the street. I chewed them up like erasers and they picked up every rock I ran over. They came off real quick plus that car makes an honest 650 HP so nothing was going to hook on the street so I went back to a street radial.
Use this calculator to give you an idea of what gear changes and tire height will do for you.