Latest 440 Source Stealth head set

I really appreciate the great service I get from 440 Source. I wish the heads were something I could say, "Just bolt 'em on." I cannot. It should be noted that I would NEVER bolt on ANY factory assembled head, OOTB, from ANY manufacturer, not Edelbrock, Indy, Brodix, Dart, RHS, 440 Source, NONE OF THEM.

Now back to the Stealth head.

I highly recommend that you use 1.5:1 ratio rocker arms on the Stealth head. Get a cam lobe that will give you the lift you want! 3/8 pushrods and 1.6:1 ratio rocker arms require extensive grinding to clear the intake port. The 1.5 rocker will give about .050" more room right from the get-go. You CAN USE the 3/8 and 1.6:1 combination and still get 345-350 cfm. We do it, but it is a balancing act.

For the most part, you could replace any Mopar factory iron head with an OOTB Stealth head and it would work just fine for a long time. I DO NOT recommend doing so.

The quality of retainer has improved in that you get a more uniform spring installed height. The older retainers would sometimes be .020" different.

I have found, very often, the valve stems are scored just below the locking groove. This seems to be caused by dragging the locks with retainer as the head is assembled. I replace (or repair if possible) 4-6 valves on each set of heads.

The locks still cut into the locking groove at the tip end, and if not filed prior to removal, will cut into the bronze guide. So I still say to replace the retainers and locks even though the box says they are using some Comp Cams parts.

The bronze guides are about .040" larger in outside diameter than the standard .502" guide. Therefore one could buy a bare head and ream the guides to 3/8, using a supply of on hand 3/8 stem valves, should they choose to do so.

The OOTB valve job will generally seal and be better than a stock head but still leaves much to be desired. I find that a few of the guides will be a little tighter than I like, though none have ever been too loose.

The valve spring pressures have been as uniform as and equal to the Edelbrock RPM head.

I haven't had any problems with casting flaws like porosity. The machined head surface is generally flat enough to seal with a composition head gasket, but we find that just clean cutting them always reveals some slight twist or warp.