I've been running my 427 for years with these heads, and they've done alright for me. I want to see what the general feeling is on the performance potential for these heads. I pulled them off a '72 402 I had, and they used these castings on the 365 HP LS-5 in '72 as well.

http://i21.photobucket.com/albums/b259/jquarles/72HeadCastingnumbers.jpg
http://i21.photobucket.com/albums/b259/jquarles/BBHeadcastings.jpg
http://i21.photobucket.com/albums/b259/jquarles/3999241X.jpg
http://i21.photobucket.com/albums/b259/jquarles/72HeadCastingnumbers.jpg

Casting #: 3999241
Application: 402/454
Year: 72
Valves: 2.06/1.77
Combustion Chamber: 113cc
Oval port

They were ported and polished, and outfitted with 2.19 / 1.88 valves when I went through them. Other than that and matching them to the intake, they're pretty basic. Current application is a 9.x:1 427.
Basically, my car is a standard street/strip deal. I've always had traction issues with it - best pass is a 13.28, best MPH was 109. I'm not sure what kind of horsepower I'm dealing with (I'm guessing somewhere in the neighborhood of 400-425), but the motor's built to pull to about 5500 or 6000 RPM (see combo in sig). Do you guys feel that these heads fit the application? What about if I step up to a 496 in the future with a mild roller?

I think you have a good running motor there. With good traction you would probably be in the mid to low 12's. That said I'd have to say that those heads are performing on par with other good factory heads.

are they open or closed chamber heads?look in internet to see i dont have a web for 70 and up heads but any body will tell you with right connections.or ask a machine shop they got books on it.if there open chamber as i suspect. putting on a closed set of chamber heads will boost compression and give you alot more power.:beers:

Most of the closed chambered heads were early heads and don't flow as well as the open chambered....plus, you will probably need to install hardened seats as leaded gasoline was available back then.


If you go to a 496 with a small roller or street roller you will probably have to invest a fair amount of money in the heads to open up the ports a bit.......might be more feasible to look into some aftermarket iron heads along the lines of Dart Iron Eagles. Those heads out of the box will give more power than hogged out factory iron oval ports......

But i don't want anyone to think I am dimunitizing the old iron ports from the factory......the reason BBC's rule the streets and the strips are becasue the heads flow like mad.

You will be fine with them. Some bowl work, larger valves, good to go for now and the 496 as long as you keep it around 6000-6200 rpm

Thanks guys! That's what I was hoping to hear. Jaguareats, they are open chambered (113 cc).