Transmission Recommended to Run Behind Built 360ci Engine in a 63 Valiant

Thanks for all the info & ideas guys, much appreciated. Looks like I will end up sending my 904 to a custom shop to get it modified & beefed up to work with a later model 360 engine. I'll give Dynamic converters a call to see if they can do the work or if they can recommend a good shop if they can't. I don't trust the local transmission shops we have here for something like that.