Transmission section for engine swap

Ok since I didn't get much info from the early A section I'll ask here. I'm doing a 360 swap in my early A and it came with a 84 727 from a truck. I assume this is a lockup converter transmission and doing the research it seems like it would do better with mileage but not sure about how it will affect performance. My question is, I'd rather use a 904 on this engine for obvious reasons like lower weight, less hp loss and just a better fit in my early A. Don't really want to beat my trans tunnel up or have my drive shaft shortened. But I'm getting conflicting reports on whether a 904 will hold up behind a 360. It's an 82 360 with 88k miles, only mods are Stealth intake and Edelbrock carb as far as I know. My understanding over the years is the 904 will handle 500hp without needing to be toughened up or switched to a 727. Is this not correct? I don't see myself making 500hp with this engine unless I go turbo or tear into the engine for more compression. So bolt ons is going to be the extent of it. So what's the answer? Anyone running 904s behind 360s?