No power

I just bought a 87 gt a couple weeks ago and finally started racing it. In first gear when I hit about 4,000 rpm the engine revs high but it feels like there is no power. This happens when I just take off from a stop without launching. around 3,000 it pulls hard with full throttle but when I hit 4,000 rpm, it seems as if the wheels might be breaking loose. It seems to do it for all gears if I am into it all the way. Please let me know if there is a problem I dont know about.
Thanks

P.S. What's the best shift point for the car? The redline is at 6k, but it feels like it dies at about 5.5k.

I've had all the fluids flushed, I just haven't had time to get a complete tune up. Hopefully that's the problem, but it still should be pulling harder then it is.

It's not the fuel filter, they replaced that when I got the fluids flushed.

I'm thinking it needs a good tune, looking to buy a new distributor and wires tonight. I'll try that clutch thing later...