Wondering how much hp and tq a stock 47re can handle before you need to do modifications?My truck has a rough estimate 300 rwhp,Don't have a lead foot(only every once in awhile), keep up on the on all the fluid changes and get the tranny flushed every 50k miles,also have an tranny cooler!But i've heard they don't like going over stock?!

 

I would say that you are at your limit. In fact, at 300hp, I bet you are speeding up the need to do trans work. IMO, when you do build it, do it once and do it right.