906 or 452 which is best overall

Man-on-wheels said
Hello everybody,
Great information on the comparison of these different casting number heads. My brother and I bought a 1978 440 out of a Chrysler new Yorker. We haven't disassembled it yet but I'm assuming it has the 452 heads. What I'm trying to find out is how many CC's the combustion chambers are? I have checked multiple websites and seen I think 4 different numbers, 81.5 , 88, 90 and 92. We don't have the tools to measure them. Does anyone know how many CC's the 452 combustion chambers are? And if they are all the same? Also, the engine is supposedly low miles so my plan was to check the valve stems for carbon buildup to see how tight the guides are. If they still look pretty good we were going to do a mild port and polish, hand lap the valve seats and install the new springs. Aren't the 452 heads better for the unleaded fuel because of the hardened seats? What's the largest valves the 452 or 906 heads will accept? And would it be cost effective to buy the largest stainless steel valves, have a 3 angle job done and mill them to achieve the desired 11/1 compression ratio?

We are planning on building a street/strip Dart (hopefully mid to high 11's or better) I really want to build a hydraulic roller, 11/1 with EZ-1 Indy cylinder heads but I'm not sure our budget is going to allow it. So I'm trying to come up with a plan B.

Thanks in advance for any information! I hope that everyone has a great day!

I'm going to answer some of the questions because it will just be fun to do it.

But, I think we better begin to contemplate a plan "C".

906 and 452 heads will be around 90cc and vary, in the same head, as much as 3cc.

The 906 head will produce the most power in the long run but the 452 is the easiest to get to the moderate flow levels.

The biggest valves in a 906 or 452? I have successfully run 2.25/1.81. But the port work to make them flow was way excessive.

If you plan on running the stock bottom end and mill the heads to achieve 11:1 compression you will have to go to about a 40cc combustion chamber and mill the heads around .250"-.300". At which time you will be removing a portion of the intake valve seat.

The good news is, engine wise, to get into the high 11's with a 440 in a Dart, you can probably do it with 8.5:1 compression, properly prepped Stealth heads, an Edelbrock RPM Performer intake, 850cfm 4 bbl and a 240-245 degree @ .050" hydraulic flat tappet cam. Done right, that's a 450 HP engine and you are under 12 seconds.

Dyno testing a stock(?) 1972 440