I put the 3.5 gears back in a couple of weeks ago and the difference was night and day. rpm at 60 is around 2800 but drives on the open road sooo much better.
had her out to 120mph with 10 psi boost and **** loads more in her yet.
Sounds awesome , post a video if available .... Fwiw : Full synthetic automatic trans fluid doesn't break down until 450-500 degrees farenheit. Normal automatic transmission fluid, starts breaking down quickly about 220-250 farenheit. You may know this already. Went through this , with a over loose converter years ago.