why a custom built converter isn't for everyone....

You need to get the right converter for your combination or in your case, keep modifying things until you get to a point where you need a different converter. Cam size, rear gear and rear tire size seem to be the most important. Yes, you could get a completely wrong converter for your combination. Put a big cam in that idles at 1000+ with a stock converter and you need a higher stall. If it doesn't make power until 3000+ you need a higher stall for it to work good/better.