400 horsepower low compression 360

I've had 4200+ converters that drove like a stock unit for the most part. Not all converters are created equal and if it drives like stepping on a marshmellow, you need a different piece.

OP has a 4 spd, the auto trans talk is irrelevant. You can do a bunch more with the cam and a 4 speed not having to deal with in gear drag down.

I have a Dart 340 with a 528 mechanical, ld340, 4 speed and 3.23's, 26" tall rear tires. It's fine to drive and responds really nice.

As far as calling the pros, PRH, OU812, Sean NCengine, RAMM sure. There are a bunch of really sharp people in here that have done this stuff a LONG time as well, TT5.9, JYH, Justin, 1wild, I'm forgetting a few others. Better than calling the desk jockeys at some cam companies that never built a thing unless you got to talk with Billy when at comp.