Radials are not recommended for 4-speed cars. Just ask the tire manufacturers. The sidewall on radials are stiff and then they require more air pressure for less rolling resistance. This is why radial tires are faster. In Stock Eliminator everybody runs radial slicks, except the 4-speed guys. Radials are not forgiving enough for four speed cars. When a radial starts to spin they don't stop. I run M/T pro drag radials on the Stocker Volare and my Challenger. They require a lot of chassis tuning to work on a consistent basis. You would be better off going to a true drag slick for the best results. Our Duster runs a M/T 28*9 slicks and runs 11.50's at 3200lbs with stock suspension. Good luck.