Buyer beware on the Eddy's that I have seen lately. I haven't seen the sidewinders in person yet but they look like the Renegade heads that I buy from Motorville. The castings are ok and it sounds like they are finishing them out properly. I'm building a set of 906 for myself. I like a challenge.

Rough cut on the intake port. This is 250 cfm with the 2.08 valve.

You know, as I sat here and thought about this, I just realized that I've never bought a set of Aluminum BB mopar heads new at retail.

Edelbrock RPM set, NIB, 1150$ from a Moparts member who had changed directions and was going Indy.

I ran these heads for 9 years, blew up two short blocks under them, had a buddy port match the runners to the intake, and clean up the bowls. After it was all done, I sold them to my brother for 1000$, with the Isky ductile rockers I had on them. My brother has three years on them with nary a problem.

Indy -1 top end kit, NIB, 2450$ was the third owner, they were never used, and had been sitting on a shelf for five years. I sent them to IMM with the intake, had both fully ported and set up with roller cam springs (1600$), sold the Indy rockers and bought a set of T&D's (950$) in 2007. Then put them on my shelf...someday, I'll use them.

Indy -1, ported jesel rockers, spray bar oiling, bolted to a low deck aluminum Indy block at 512 inches. Puchased entire used engine for 10K.

Indy SR set used 3200$ MW Ported, ported Indy intake, 1250 Gold Claw, Racer Brown Aluminum Rockers, Indy valve covers. Purchased from my brother, after he bought Moparts member Atoetly's complete engine.

Modern Cyl head CNC ported Stealths 1700$ from Moparts member. Bolted straight on the hyd. cammed 440 in my Belvedere to replace cracked, ported 915s. Love them so far, two years on them.

Between my 3 brothers and my dad, they've had another set of modern cnc Stealths, two sets of ootb stock stealths (bolted on and ran, no problems). Two more sets of Indy SR heads, two sets of Indy EZs and three or four sets of Indy-1s, as well as a set of Stage VIs that we repaired about a dozen times.

We just won't even bother with cast iron any more, not worth the time to port them, and then have them crack a few years later.

Im not suggesting anyone spend a lot of money on iron heads. I build cylinder heads. Its just my thing.

I think the Stealth head is the only one that had an external appearance like a stock head if that matters to you.
Several of the cylinder heads have different combustion chamber volumes so you compression ratio will changed depending on the heads.
Out of the box flow numbers vary. I think you can find some of the "real" flow numbers by searching the forums?
I have not seen any information on the quality of the valves, valve guides, and valve seats used in the heads?
For a stock port window big block head, the new trick flow heads look like a good deal.
Also, some heads use offset rocker arms (Indy, Victor, B1, Stage VI)
I haven't seen the sidewinder heads? Look like a copy of the RPM heads?

What engine are you building, and application?

I was ready to pull the trigger on a pair of EZ's when some Stealth's came up locally. They had the springs, locks and retainers changed but we're NIB.

I ran them unported on a low compression 440 with a cam, intake and headers. Did the swap from 906's in a weekend. Lots of fun! Drove it everywhere for a few months but I liked to rev it and had a stock, heavy piston come loose from a wrist pin.

Heads were fine with only two bent valves. I sent them to Modern Cylinder Head for porting and built a 505" stroker shortblock.

It recently came together and was AMAZING! Ufortunately I lost a cam a week after break in. It's apart and getting a roller right now. No more flat tappet solids!

Everyone that looks at it thinks they are stock heads. I really like the sleeper aspect as I painted the Street Dominator intake too.

The transition from a 8:1 CR 440" with stock 906 heads and cast iron intake to a 11:1 CR 505" with cnc ported Stealth's and a Holley Street Dominator is STARTLING!

I would not have a problem purchasing any of the heads listed but sure do like the sneaky factor of a Stealth.