a500 ?
For the converter just grab a gopnh.com OEM hi-stall or whatever you need and get r done.
I think that most people talk out of their a$$ when it comes to the a500/42RH 'beef up'. Just parroting information they read vs. first had experiences.
Dudes, it's an a904 with a OD bolted to the back, hog out the OD feed hole, maaaaybe add a couple clutches and steels and let it roll!