3/8 should be fine, unless you are gonna blast for 1/4 mile at 6000 rpm, then you might
run outta fuel, but your carb bowls would have to empty first.
I have 3/8 on my 496.
If went 1/2 inch, would have to make sure there were no other 3/8 inch restrictions, like at the tank pickup
or at the fuel pump. Otherwise, all the 1/2 inch line would be wasted.