Hadn't considered heat dissipation. I was thinking more simply about the burn having more surface area to push down on per stroke and wondering if there is a decent way to estimate how much additional power was possible just on that factor alone.
I bet it does have a positive effect because as the bore size increases, compression increases along with it plus a better draw.
I guess to really tell you 100% id have to build a stock bore engine and transfer everything out of and off of my 470 , that would be a very interesting test.
Id also like to machine another block and hard block it with 4.500 inch bore sleeves to see what that would do, it would probably dissipate less heat though and I don't have enough cylinder head for that yet