Need everyone's oppinion

As some of you may know i'm pretty sure i have blown up my 7 1/4 in my duster. My dad and i have been arguing for the past few days on which way to go about dealing with this issue. I'm thinking swapping an 8 3/4 with a 489 pig with a suregrip. But my dad on the other hand wants me to buy a new Dana 60 and not worry about anything breaking. I always thought the 8 3/4 was pretty much indestructible? My thought is that my car only has a 318 that has been bored .030 over, Aerohead racing 360 heads that have been gasket matched, an edelbrock performer intake that was also gasket matched and a mild comp cam so a Dana 60 would be overkill. Any info is greatly appreciated! :cheers: