Bigger valves in 302 heads?

If you port them in the process, short turn blending, then they will help...if not, they might could actually hurt flow due the big overhang of the short turn..but that could be remedied somewhat if a multi angle cutter that does a nice throat cut is used... but typical without porting/blending the short turn just becomes steaper...and the flow sometimesdrops off at an earlier/lower lift.
We have a machinist that uses something like a custom 7 angle cutter , it does a really nice chamber bowl cut/'well' looking blend from the chamber to the seat and the valve job alone picks up 10-15 cfm on average.