I have a customer who has to many motors and wants me to put a set of economical price aluminum cylinder heads on his 383 forged piston short block. That motor had a set of 440 Source ported Stealth heads on it that he had me use on one of his bigger C.I. pump gas stroker motors for his street 1971 Challenger.
Has anyone on here used any of them, shops or individuals
If so what are your thoughts on them, good or bad
I seen them on Summit and found out that they are owned and made by the same company, China made imports also


MODS, what's up with the time stamps on here it is 10:55 PM PDT here in Bend, OR not 5:55 A.M.

im guessing he dont want to buy a better set

I run a set of procomp, which I think with name changes is speed master now, not sure. But they are a copy of the Edelbrock Victor Jr. At the time I bought them, I knew I was going to port them and remove a lot of material so I wanted to screw up a cheap set, not a good set of heads experimenting. They worked out good so I have just used them for several years. I did however buy good valves, springs, retainers, and these heads require offset rockers, so nothing was really cheap about them. If you are going to use standard rockers, the ported stealth heads would be a decent choice. All the good big block mopar heads require offset rockers, which really drives up the cost. I have not run any of the trick flow heads everybody is talking about. But just from what I have seen all the cheaper knock offs that use straight rockers all flow similar, not much difference in performance. Some of the guys on here that build more engines than me may have different experience

I put them in the same category as the stealths........ perhaps the stealth valve job is more consistent.
I always redo that anyway, so that’s not a factor for me.

I have seen some SM valve jobs that really needed some attention, so plan for that if you go that route.

When the SM aren’t on sale, I think the stealths are cheaper.

SM are available as straight or angle plug.

I had some SM here that showed in the specs on line that they were 75cc chambers.
They were not......... they were 84cc.

The intake port openings are somewhat oddly shaped, with the port divider being way wider/thicker than the gasket.

Valley pan centered on bolt holes, plus ex port opening.

The stealths are better from these two views imo.

Remachined seats & tweaked in/ex openings:

i was just about to order some trick flows to replace my stealths

If you have the cnc ported stealths, it won’t be a big change.

If they’re ootb or just “prepped”, you should see a nice improvement........ provided you have enough motor to use it.

just 440 like 10 to 1 solid cam

im a small block guy

I have the sidewinder heads from marsh performance. I hear they are the same casting. I got them bare with valves for $849 iirc. My head porter traded me some work to build them so cost for me was 1200 ported with good springs locks retainers.
They have roughly the same potential as a rpm if you plan to port them. They seem to be a good quality aluminum and a good casting.
My porter did mention he thought the short side was shorter than a rpm, kind of like a 516 head.
But I’ve seen Duane and others on here say these are the easiest head of the budget ones to get 300cfm.
I go straight to a better head if the port work wasn’t free. By the time you put all the work into these you’re only 2-300 dollars less then a trick flow. To me these days just getting trick flows is a no brainer for this category of performance heads.

the Promaxx heads are supposed to have a nice valve job and some bowl blending. for about $1150 with hyd. roller style springs...

sounds good to me

If I were building something here and was planning on using a budget oriented aftermarket head it would get E Streets.
Ede heads have high quality guides and and I have more faith in the hardware.

I always check them over........ and I usually end up honing the guides a bit and touching up the valve job.

I talked to Marsh performance the other day about my under performing 511 with the Victor MW heads. He is one of the few that likes this head and said he made over 1000hp with this head. He has a few top cylinder head guys like Larry Smith and Rex Hathcock I think he said. Also Roger Penske porter as well. So will some fancy work they can make power. He really likes the victor copy cat head for the money, claims over 800hp with the copy cat head. Not sure what the trick flow 270 is capable of max power for comparison.

do they come cnc already

I'm running a set of Promaxx BB heads. I upgraded the springs, locks and retainers to Comp Cams stuff that is matched to my .528 MP solid cam. I have only made a couple of passes since the head swap. With my big valve 906's my best e.t. was 12.55 @107.75. With the Promaxx's my best pass out of 2 was 12.64 @108.5 with no tuning. Also, that track was at 3,500 ft. Elevation vs my home track at 500 ft elevation. So, corrected it came out to like, a 12.28 pass. I still have a lot of tuning to do as well as practicing my launch technique. My 60' is pretty weak.. 1.84-1.90 range. But over all I'm happy with the Promaxx's.

kool

Not trying to stir the pot, BUT is this true on the Sidewinder Dwayne ? But I’ve seen Duane and others on here say these are the easiest head of the budget ones to get 300cfm.

My neighbor just build a 493" RB with out of the box E Streets.

His machinist said they were good to go out of the box.

With a very mild cam it made an easy 500 HP.