My sons car will literally 60' 1.40's anywhere . Its caltracs with a 295 radial. He has Afco double adj out back and the calvert 90/10 up front. We run the Afcos full tight on the extension and almost full tight on the compression. Now we are a nitrous car, with no progressive or launch retard, we literally spray a plate .
Im not sure about the front segment of an E body Spring , as an A body spring is short and really slams the tire We just got the Afcos revalved to a "radial" valving. I would say with the radial tight is better, now if it doesnt hook, loosen the extension a little at a time. You want the car to plant the tire and hold it there. Pressure on a radial is usually higher than a slick. You dont want to wrinkle the tire because it will snap back and tire shake. We run the 295 at 20lbs, sometimes as much as 22. Even on my Ultra street car, we run the tire 17.5 to 19 depend on track. Rim size also effects the tire pressure. A wider rim needs more air to keep the tire from cupping in the center.