"rev to 4-5000 release the clutch & the car drops to about 800rpm before slowly picking up"
^this bit had me curious, is your clutch in any good shape??
but yeah, your dizzy/dizzy cap could be fairly fried (especially if you have aftermarket headers and no heat-shield), coil/ignitor could be on its way out, timing could be off
not many other things it could be imo, i think when rob's fuel pump started dying it had similar symptoms
compression test is always a good idea, but i really don't think that it's the problem in this case