Afaik most aftermarket th350s have the kickdown stuff removed. Find a good short shaft bop th350 on CL for $150, and put a trans go 350-1-2 kit in it. Even with my wheezy 350 it would chirp 2nd. Shifts are quick and crisp but not hard and bang-y like B&M. I had the orange(?) "Street" spring in as well.
Which wheezy 350 is that? The one with the comp cam or the one with hole in the block where the starter used to be? 🙃