Thanks for all of the responses, I'm going to go with the 2500 Hughes matched up with the Comp Cams Extreme Energy XE268 cam. The guy who had the car built (before I owned it) went with a super mild cam prior, which is what it has currently, a Crower hydraulic flat cam with a duration of 204-210, it was installed like 15 years ago, I just want something with more power that will have a meaner sounding idle. If I go with anything larger than the XE268 we would have to replace a bunch of other shit, I'm already spending a fair amount of money on new suspension and installing a charcoal canister system to reduce the gas smell, so the XE268 should work.
This is a modulator and/or governor issue. stall converter will only affect manifold vacuum slightly here which affects the modulator. you most likely need to calibrate the modulator and governor. also do you have the kick down switch wired in?? most people that do a th400 install forget to do this then complain about full throttle stacked or super short shift points. if the switching is done correctly it will make a th400 very friendly to drive.
Yes, the kick down switch is wired in and works well (downshifts as expected when you romp on the throttle).
Ken in SSF California - 56 One-Fifty Two-Door Sedan