Those are the first Generation of Aluminum Magnum Heads. They were basically a Cammando head they was machined for use in a Magnum Application.

When they were Available through Mopar's catalog they weren't. Now that they aren't any more they have been popping up a lot in various places. Indy had a bunch of them as well as some Ebay dealer out of Dodge Indiana. I bought a set from the Ebay dealer for $500/pr.

Supposedly they can be made to flow around 300cfm, or compariable to an Edelbrock head.

One thing I found out with mine which were missing 1/2 the seats and needed the guides replaced, Is they will only hold about a 2.05" intake valve MAX.

One shop that I know that has done a few sets also said that they found that some of the casting seemed a bit soft as though they had never been heat treated. He had the ones he did Heat Treated.

On the flip side if you look to Mopar for Magnum Aluminum Heads NOW all you will get is Edelbrocks with MOPAR on them.

Also after dropping mine off at the machine shop and the guy looking them over YOU'd be better off buying the Edelbrocks if you're buying new. I could have bought Edelbrocks Complete ready to go and saved a few dollars over what it's going to cost to complete or fix the issues from the ones I bought. And they weren't even used heads. Just never finished.