trans fluid

A "stall converter"? So you want to convert stalling into something else like perhaps moving? Okay, pet peve of mine, I hate that term. It makes it sound like you are some wife beating loser who drives a primer grey Camaro and reads Car Craft. Nothing personal, but calling parts by their correct names will boost your credibility and help you get good advice.

What you mean to say is that you wish to install a "Torque Converter" with a higher "stall speed in RPM". All torque converters have a stall speed, but for performance usage, we generally want our converters to stall at a higher RPM so the engine gets higher into its powerband sooner. However, if the engine is turning more RPMs at launch, and making more power, and the converter hasnt "stalled" yet and started the vehicle rolling, ALL of the energy the engine is putting out becomes heat. So, yes a secondary cooler is a good plan as would be a deeper sump.

As far as fluid goes, I'd run Dexron III for a couple of reasons. First, the only automatic transmission failure I have ever experienced as a 904 shortly after I converted to Type F. The trans had 230K miles on it, so I really cant blame the fluid. But the second reason is loooking toward the future. Nothing has been built to use Type F for over 20 years, yet Dexron III is used in new cars today. So what happens down the road when you have to add a quart and cant get the right flavor of cherry juice? Type F is getting harder to find. Remember Type A?