I have 74' 454 with the O49 oval port heads on it. I am pretty sure it still has the 2.06 intake valve and the 1.72 exhaust valve. I don't want to spend the 3,000 dollars on the AFR CNC 315's just yet. Plus I like the sneakyness of saying it is an iron headed 396. I have ported heads before and would be willing to put in the time on these heads if they are worth it. The stock flow is about 264 int. at .600 and 173 exh. at .600. I was figureing with larger valves and some port work I could get them over 300 and 200 respectivly. Do you guys think this is possoble or even worth the effort. Is there some kind of design flaw that would hinder this. I was looking to make 600 hp with a solid roller cam. Any advice would be appreciated. Thanks.

 

You can certainly make 600 h.p. with those heads.
You will need to spend probably 400-800 depending on
who you know or what you can do yourself.It would require
2.19/1.88 valves, a gasket match, and decent bowl work.
I would also backcut the valves.

 

I back cut all of my valves. There is a ton of low lift air there. That and a good chamber blend. I was thinking of taking about a sixteenth from the outer wall and the port roof. Then taking the bowl out to 88% of the valve width. I was going to go with the Milodon Mega Flow valves in the 2.19 / 1.88. I just don't know if I will have to go with 0.100" longer valves to accomodate the .670 valve lift I intend to use.

 

As far as the longer valves goes, it would probably depend
on the installed height of the valvesprings,which would be dictated by the cam in question.I wouldn't go hogging out the ports as it really isn't needed.Just a good bowl blend and the blending of the short side radius, and gasket match.I do remove
ALL casting flash through the entire length of the port though.
Also, teardropping the guide bosses can be quite beneficial.

 

I talked to a guy to day that did a block for my friend. He said he has three Camaros in the 9.30's with 454's and O49 heads. All he wants is $600 to do all the work including valves and spring set up. I told him I just wanted to get into the 9's on the bottle. He chuckled a little and said not to worry about that. I know he did a set of Pro Top Line 220cc heads that ended up flowing 340 cfm on the intake and 230 some thing on the exhaust. He didn't hog them out either, he just reshaped them. I will give him a shot and see what I come up with. The other thing he mentioned was that we need a system approach not just random selections. So I know he is not out there just selling numbers.