Intake port cut-away

https://www.youtube.com/watch?v=BZzudIxHY0g

Combustion chamber


https://www.youtube.com/watch?v=4op2k_k301E

That 315+ is way way more than I've gotten out of them. But, I'm usually going for the no-holes-no-tubes plan.
I think low 280's is the best I've gotten out of a basic porting job, 2.055 valve.
Those made 589hp on a 419.

This project was for a very good Friend that does my transmission work and it became a challenge project for me. They started out with me repairing a set of 400 dollar open chamber Edelbrock (340) style that I repaired then added a 2.05 valve. He was then curious how much we could get out of a 2.08 valve so I tried it. Without moving the pushrod I would NEVER do a set like this for anyone again, except for myself. A 2.05 is the way to go. He ended up never even using them and when he said he was going to sell them I bought them back because I had to much time in them to not have them. Being retired and not doing it for a living allows me to play around and I love flow testing and probing a port.

Edit

Ok, good info.

So the procomp is the same as speedmaster? I do not like what i have seen in the procomp stuff for brand x

The promaxx is different then those castings?

I was in the market for sb heads and found it very confusing

Did you watch the videos as they will answer a lot of your questions. This head is not even on the same page as the speedmaster (old procomp) and in my eyes so far is way superior than the Edelbrock.

Just to put this out there....not a reflection on the Promaxx stuff. But I would find someone that has real world experience with them from a durability standpoint. My buddy just dropped off his truck with a very nice 496 stroker BBC short block topped with offshore heads and the quality of the guides and valves wrecked the whole thing. I am talking about mushroomed valve stems to the keepers , a valve that dropped a head off with no prior evidence of touching anything, valve to piston was .270, and valve guides that are .030, yes .030, out of round.

The heads were very nice out of the box...I could not tell the metallurgical make up of the parts though.

the casting looks ok even after all the destruction......

Has anyone run these heads for any extended period of time?

And what kind of heads were these. Please don't tell me procomp speed masters because there is a crazy amount of info out there to stay away from those heads.

Those are the ProComp/ Speed Master Heads

Im in mexico. I will check them out when i get home

These were not Procomp/ Speedmasters............

Ok I always up for a good challange. I called and talked to PROMAXX in Alabama and Steven told be these are not Procomp (speedmaster) heads. 100 percent of the machining is done in house. So from this point on all the naysayers PLEASE start your own post and post any results YOU find. No wonder guys that used to pass tech on this site are in hiding and no longer post.

PROMAXX


http://www.promaxxperformance.com/index.php/racing-parts/sbc.html


PROMAXX (Speedmaster)

https://speedmaster79.com/contacts/

If you go to the speedmaster website, it says that procomp is the sole US distributor for speedmaster.
So speedmaster is procomp.

I can't speak about the SB mopar heads, but when the Sidewinder BB heads were first being talked about, one of the owners of the foundry in china confirmed that at least for the BB Mopar head that it was the same head as the ProMaxx head.

I just received a set of speedmaster BB mopar heads, and I can see no difference between these and the Sidewinder heads. They even came in the same looking box.

My guess is, the speedmaster/procomp/ProMaxx SB mopar head is all the same casting.

Watch the videos on the valve guides. procomp like I said changed their name to Speedmaster because of poor reviews. They are sold right of the ship from China like all the junk electrical products. ProMaxx too recieves them off the ship from Chine as a rare casting then machined in-house adding to the price of the Speedmaster product. I'm done.

I don't doubt the guides are better. When ProMaxx was Patriot they used to advertise that the guides were made and sized in the USA.

Edit- just checked one of my catalogs for ProMaxx, says all heads come with USA made guides.

Edit

Edit

to Bad our Promaxx heads didn't stand a few mile in a Little red....
a valve spring broke in 3 pieces and dropped a valve......

BUMMER.........

Can I see some pictures of the head PLEASE. Front, back, ex side, and intake side please.