Oh yah.  Heads too.  I also have a brand new set of late casting 452 heads.  I've always heard 906's are the best, but I got these because of the hardened seats.  How much work and massaging will these heads need to make a good healthy street engine.  It'll probably never see the 1/4 mile.  I just want that pin you back acceleration 440 feeling.  

The best cylinder head depends on the application. The 906 and 452 castings are basically identical, with the 452s having hardened seats. Both the 906 and 452 castings have decent ports and runners and decent size valves, and respond well to porting in the bowl and pushrod pinch area of the intake port.

These are open chamber heads, however, so they lack a good "quench" area in the combustion chamber. Bolting these heads on a later 440 with pistons way down in the hole will result in miserably low compression. These heads are best used with flat-top pistons right at the top of the bore at tdc.  

Thanks Badfish,  I know there open chamber heads, the piston I was going to use is the Kieth Black KB184.  It's supposed to have a comp hieght of 1.978" and valve reliefs and a quench dome.  The catalog says 9.2 to 9.7 compression depending on head cc.   What is the head cc on the later castings?  Do you think opening up the exhaust to the 1.81 " would help much?  

in reference to your knowledge on heads, what cc pistons would the most you would dare to install with stock 452 or 906 heads and still drive on todays gas and have a 9.5 or 9.7 comp ratio? I understand these heads left approx 88cc, is this right?

please email me at mel@moparmel.com  

thanks in advance  

Could you restate your question christineman. I'm not sure I know what your asking me.