Need Tranny Help

I'm looking for a automatic w/ 4 gears to put in my 89 formula. It's got the 305 5L. I want something with balls because i'll be putting alot into the engine. I plan on installing a manual valve body to the tranny. What specific tranny should i be looking for? Thanks

Your best bet is either 700R4 or the 4L60E. Try some aftermarket transmission makers to see if the application will handle your specific needs.