[Mad Maggot]

I was lucky enough to find some 915 closed chamber mopar big block heads on Ebay recently to use on a numbers matching 440 Magnum from 1967. I am planning to hop up this motor for a Charger restoration. I want to know what are the biggest valve sizes that will fit into these heads, since they need new seats and valves anyway. The extra valve size will help with the short side radius and will improve flow considerably once I port the heads. I want to focus on making the intake valve as big as possible if that matters at all.

 

[bracketeer]

not a mopar guy

I tried to find you some info. The biggest I found was a 2.18. There may very well be bigger.

 

[Mad Maggot]

I remember seeing 2.25/1.81, but that may have been for a Chevy head. Since these are going into a .060 over 440, I don't think shrouding will be a big issue with large valves.

 

[NAIRB]

The standard large size performance valve for a 440 head would be 2.11 and 1.81" These, I believe were the size the max wedge engines used, and to upgrade a set of stock 440 heads, that's as big as you should probably go.

 

[Mad Maggot]

I believe the 1964 max wedge heads used 2.18/1.88 valves but I could be wrong... I will have to check on that.