There is a saying amoung older racers," make one change at a time"
saying this i would remove all your mods except one and see if your time improves,, if yes add another retest if no take that one off and put another retest,,,here example you put pully, 103oct.race gass,, and drag radials and go slower than stock,, maybe the tires are too tall,, maybe the belt is slipping on the pully,, or maybe the gas is too hot for your stock engine,, now go back and put only the tires on retest, you went faster,, then add the pully, retest you went faster,, now add the race gas retest, you slowed down, it's the gas this is why we add one mod at a time. good luck jim