I am going to build a 440 for my 66 belvedere II for the street and sometimes to drag race on the weekends. I have three different casting number sets of heads at my shop. I was wondering which would be the best.
3462346 81.5cc 2.08 1.74 valves
2843906 79.5cc same size valves (I have been told the best).
4006452 81.5cc same size valves.

Does the larger combustion chamber size make any more power? Any ideas would be appreciated

 

i have heard the 906 heads are the best.

 

Ok 1st off no the larger combustion chamber doesn't make any more power. The 906 heads have virtually the same flow characteristics as the 452's However the 452's have hardened seats in them, so if you're building them that will save you a few bucks. I didn't know this, and I had a set of 906's built, and I found out later I could've saved money . grrrrrrr.

Now granted I mud race, but is there any reason why you are wanting factory castings? I have to run them (stupid rules = OEM castings only), but it is actually cheaper to go to the Edelbrock Performer heads, than it is to have the factory castings built, ported, large valves etc etc..

just my .02

 

Well, I've done a bit of research recently on stock heads and found the comparison story on mopar muscle site.
I have a set of 346's and after a little tickle up, they beat the other tested heads for outright flow....
http://www.moparmusclemagazine.com/t...ads/index.html

But after lifting the heavy buggers off the block, I might go alloy, I think!

 

Use the 906 heads if you dont want to spend the money on aftermarket heads, and a smaller combustion chamber means a higher compression ratio

 

I think INDY are the best but also pricy
http://www.indyheads.com/