help car lost all bottom end

[james87gt]

I have an 87 with some bolt ons but anyway the car has no bottom end at all any more I can't even chirp second or fishtail a turn. If I stump on the gas it feels like the clutch is slipping but its new the motor sounds like its going really fast but just revs up slow and then it pulls pretty good up top it also backfires sometimes when I get on it. Iv checked everything I can think of so if you have any ideas please post them and im sorry for the description of the problem its hard to explain, but basically if I punch the gas the car does not pull it revs up slow and then at like 3000rpm it starts to pull.