[Formulajones]

I run 275/60-15's on a stock pontiac rally on my 70 formula with it's original 12 bolt rear. It is stock ride height with it's original 44 year old springs and the tires clear with room to spare. No rubbing while driving, turning, or even entering curbed driveways at odd angles. Even carry the entire family in it, along with a large cooler and lawn chairs, still no rub with extra weight.

These tires have a 8.9" tread width and 11" section width.

[torqjunki]

28-10's will fit on the wheels, but will suck the sidewalls in so bad, that the slick becomes round where it meets the road and dangerous on a car with some power. Traction will be much better with a tall 9" slick. I tried the 10" slicks on pontiac wheels recently and was all over the track with a mid 11 sec car. There was close to an inch of tread on both sides of the tires that appeared to not be touching the track.

[AdamIsAdam]

Here's a tip from the off roading crowd that we use for finding the optimal PSI on 12.5" wide tires mounted on 8" rims (a common practice). It's the chalk test. If you know this already, stop reading and accept my apologies.

Get to a very flat parking lot. Use chalk to mark a line across your tread on each tire. Roll forward a few revolutions then get out and see where the chalk is rubbing off from contact. If the edges are clearly not touching, lower the PSI and repeat the process as many times as necessary to get it right.

I run 28 PSI on the street ( and about 10-12 PSI on the trail depending on conditions).

Clearly this is for a different type of tire and condition, but it may be helpful for you.

[torqjunki]

You may notice at the drag strip, the somewhat new trend is to run a wheel that is wider than the tread. It must work, everyone with space is doing it. As a side note on the street wheels, I see your running the nitto's. Judging by the size, I would say your running the 555's. I have a set also but recently replaced them with Nitto Invo's in size 255/50/17. They are 27" tall but obviously near an inch narrower. They look better on the car and traction is much much better especially on asphalt. THe taller tire will tame the gears on the street as well.