[dci]

When I measure the casting I have the same way Jim measures his in pic 1, I get 4.475.In my opinion that's close enough to call the same. All the guides are in mine so I cannot get a measurement the same as Jim's for the spring pocket, but if I measure from the unmachined part of the casting down to the spring seat. I get a depth or around .252 to .256 deep.
So unless Edelbrock machines the deck surface differently, it appears that the castings are the same. It looks to me like what they done is use the same casting just made two different intake port cores and raised the 11 degree port up a little higher to begin with. Nothing that good head porter couldn't do on his own when porting.

Jim, I don't know if you can get an accurate measurement off the valve cover rail on the intake side, but if you can I get about 4.700 to the deck.

Curt, I think I could probably get 500 cfm out of one of these heads, but it will not happen without ALLOT of welding and ALLOT of work. And we all know that means ALLOT of money.

Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the DCI Tiger Heads ad the NEW DCI Ram Air V Heads !!!!