Matt, Both engines ran the Comp Cams .557" lift street roller (23-742-9) is the part number. I love seeing the real world numbers for flow on these heads. They confirm what I thought was the case. Does anyone have flow numbers for 906/452 heads, ported with large valves? It would be nice as a comparison.
What did you think, they're not flowing much better than stock heads with 2.14/1.81s? The port is significantly bigger though.
TBH I've been trying to figure out why my Stealth headed engine doesn't rock like it should. I had a head off a couple of weeks ago and was tempted to bring it to my machinist to flow it. I went through them, lapped the valves (looked good), and changed the springs, but the ports and valve job are just OOTB.
Its not hard to get a set of 906s to flow what these heads are flowing. I'd think cleaning up a bowls a little, and big valves, and they'd be there. Mr Porter knows for sure how much is required to get them there.
Its certainly very possible your ported iron heads flowed better. I think 906s can safely flow around 280 and not risk cracking from being too thin. Some people get over 300 out of them.
