68 Firebird - Tire and Wheel size combinations

[wastntim]

I am getting ready to pull the trigger on Speedtech Extreme subframe and torque arm combination with a 9" rearend. I need to know where I'm going with the rear tires. Jay from Speedtech recommended 19x10 with a 325 on the rear and 18 or 19 on the front with 275.

I'm looking for recommendations on wheel size and tires - both size and make. I used to have a viper and had PS2.

This car is going to be an LS - 500-600 hp and will 95% street and maybe a little autocross.

Someone told me to stay away from 19's as it is an "off size".