W2 head porting observations help needed!

My old 3/8 stem 2.02 valve W2 heads hit [email protected] and fell on their face. A standard 60-45-30 valve job and a what I would call quick porting work they were up over 300cfm. Like I’ve said on W2 post before my econo heads were the number that were prone to cracking, which they did two years later, so I didn’t spend a lot of time on them. I easily ran 9.80’s at 2800 pounds on pump gas (Bp93) on my 408 with a Racer Brown .520 lift solid lifter cam.