Been trying to work out a problem with my new tranny with no luck yet, but I was surfing some past posts and found someone who had a problem similiar to mine and he said that it replaced the converter and it fixed the problem. The problem is, if I'm going over 40 or so, and I put it to the floor, the motor will free rev to about 4500 rpm then bang into gear. But if I'm going slow enough, it will downshift into first like it's supposed to and everything is well. The first time I took the trans back out, I called the guy who built it and we both agreed that it sounded like the input sprag and he put a new one in but it was doing the same exact thing after I put the trans back in. So could a bad converter act sh*tty under some conditions but fine under others? such as fine downshifting into 1st but crappy when going to second? Any help would be greatly appreciated.

 

Could be the converter, try PMing either transfixleo or probuiltautomatics.