[Berg]

ditto on leaving the PG. They are great transmissions and it'll live forever behind your 307 as long as you aren't doing the neutral drop special. If you really wanted a big improvement it would be in the lines of the 700R4 with a corvette servo. A stall converter is only good if your engine is built to launch at a higher RPM. Keep in mind they create more heat inside a transmission also. In your case it sounds like a stock converter would work best. Another advantage to the 700R4 would be the low first gear and the OD obviously. It also depends on your rearend gear too. If you are running a 2.73 gear the overdrive wouldn't be of much use unless you are looking to set a land speed record but in that case the 1st gear would be awesome.