[budgetmaster]

The aluminum d.s. should smooth some of that shake out. It smoothed my whole driveline out a lot, but even when new the shifter will vibrate around a bit. If it has had an aftermarket shifter it's whole life and not abused it will be o.k. most likely.

Try pullies, yank air silencer, timing, new O2 sensors, an off-road h-pipe, and gears. Nitrous may be easier on the high mileage motor than a supercharger, since it is used far less.

Personally, I feel big cams, heads, etc. give up some to a lot of the enjoyment of driving a mustang at light-part throttle in a daily routine. I've had both and found the stock-type mustang w/ nitrous is more fun to drive in traffic, etc. and faster than most of the head and cam cars when on the bottle. Just an opinion.