traction problems

[flips72]

i am running a 275/60/15 m/t drag radial and cant consistently get it to hook, just wondering what kind of tire pressures and how long of a burnout your doing. my set up is a 65 fleetside stock suspension except for a 4 inch lowering spring, 4.10 gears, turbo 350 leaving off the foot brake at several different rpms, tci 3500 stall, basically everything is stock except fuel tank is in the rear, healthy 406 sbc and a 150 shot. any help would be appreciated. my 60 foot ranges from 1.510 to who knows.