What I’ve seen with regards to stock, or “stock type” Gen II hemi heads is........ they don’t flow as well as what many people think they flow...... without fairly substantial porting done to them.

Stock 559’s with only the valve job touched up are a little over 300@.700.
The MP 559 replacements can be about 15-20 better, depending on which version 559-M it is.

The Ede made MP heads are in the 320 range ootb.

The Indy SR with a VJ and very mild bowl blend is in the mid-330’s.

The basic shapes of the ports are good on all the heads.
So, after they get the seats redone and bowls blended....... if you’re looking for a significant improvement in flow....... they just need to be made “bigger”.


If you’re building something with enough cubes to utilize a bigger head..... the assembled Ede Victors are over 400cfm ootb.