I have decided on a 4L80E to replace the TH400 behind my 455. I have run a 2200 rpm converter and been very happy. I do not run at the track, but occasionally street race and now have power tour dreams. Just wondering what thoughts you guys have on the new lock up torque converter and what stall it should have? I saw JW was making one a few years back, at a reasonable fee, but I thought the stall was a little high. I do have 3.55 gears, which I think are perfect for the BBB. I have settled on Extreme Automatics here in Cincinnati to build the trans, but they farm out their torque converters to Circle D.
Talk to Jim about the 4L80E too. I think he has installed them. Some good info on this site too, like: https://www.v8buick.com/index.php?threads/4l80e-behind-a-455-info-needed.297332/ Good choice on Extreme - I used them and am very happy with them!
I also have a 3:55 with the 4L80. I made a special ordered in to PTC for a 2800 or so stall, for my combination, but now after some driving, and very little racing it, it feels more like a 3200. I don't mind the slippage because it does make the car feel stronger on the bottom end and the slippage is only noticeable in 4th gear. Once locked up the slippage goes away. As per my tranny guy, he says that's the beauty of the lock-up. With this combination it cruises at 70 mph at 2300 rpm. Hope this info helps you. Fernando
