My turbo 400 was rebuilt and installed with a stage 1 rated converter when I had a 350 engine and was working on putting together my 455. It shifted very firm and barked second when the throttle was mashed. I have since put my 455 in and also a Coan stall converter only to have it shift totally different. I have adjusted the vacum modulator in a few turns which firmed up the part throttle shift but it didn't do much for the WOT shifts. Any ideas on what I can do would be very helpful. Thanks Steve
A higher stall converter will definitely soften the shifts. If you have an issue with the shifts getting softer at only WOT, look at the fluid level and a deeper pan/pickup may correct it.
