[Doug I]

I agree with Roscoe - for a street car I'd go with the bigger engine for the same horsepower. It isn't working as hard and will (all else being equal) last longer. But that's just me.

351 cost is about the same - 1 company does a 325HP 302 for the same price as a 410HP351. Both those HP's will get you in a whole world of trouble if you bust them loose at the wrong time ....

I think (others will confirm) that there may be an advantage with the 302 in autocross - slightly lighter engine which helps when you are go-left-right-stop-go-right-left-right-left-stop-go-right etc

There is an issue with the heat a BB puts out (roasting your feet in the footwells) - but a 351 isn't really a big block - so that shouldn't be much of an issue - but I'd insulate the footwells regardless of the HP you use.

regards