well i've been playing around with full slicks now (mt 28x10.5-15s) for about 5 track days and about 35-40 passes and i'm really get use to them now especially with the fully calvert suspension set up.
i've played with pressures alot ranging from 12-20psi. i will hook hard with the set up between 12-16psi but i am having the best luck with 14psi. however when i run 12-13psi i can get the tires lifted off the ground the highest and surprise the hell out of me and fellow sportman racers, HOWEVER i am swaying side to side inside of the car the whole time. i have to make sure my steering wheel is vised gripped to my still arm not to move while i'm smashing the gas and shifting. its kind of scary but i got her down for when i do it. i run 14psi i don't have that swaying issue and i can keep my MPH up higher but my 60ft only suffers maybe .02-.04 and i could barely or of any at all lift the tires off the ground.
i tried out 13.5 on a 60 degree night recently with a shock setting of 8 (usually run 7) with some success but lost 1-2mph at the top end.
i am hearing that guys with smaller slicks have to run higher pressures. but i know buys with 9 inch slicks running 10-12psi no problem but of course they are running lighter cars.
my car is a 73 mach 1 with gutted interior with a 10pt roll cage and only use 2 kirkey seats.
recommendations would be great to help out the slick issue. my 60ft is usually in the 1.671-1.703 but most of the time i'm hooking pretty hard but i think with a tko600 w/ a 2.87 1st gear, mild 460, 3.70 gears and a 3800 stall, i should be hitting 1.5xx 60fts.