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Promaxx small bore LS3 heads...

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Old Dec 18, 2019 | 05:21 PM
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Default Promaxx small bore LS3 heads...

Sounds promising...

https://www.lsxmag.com/features/pri-...an-the-market/
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Old Dec 18, 2019 | 05:52 PM
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knock-off Mast small bore LS3's?
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Old Dec 27, 2019 | 11:28 AM
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These heads will be more affordable than the Mast versions. Just waiting on pricing.
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Old Dec 27, 2019 | 09:01 PM
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Hopefully they have smaller chambers than LS3 heads.
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Old Jan 19, 2020 | 03:03 AM
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anyone heard anymore about these?
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Old Apr 29, 2020 | 04:59 PM
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Still no word on these. I cant find any info
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Old May 6, 2020 | 09:04 AM
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Originally Posted by Darth_V8r
knock-off Mast small bore LS3's?
likely yes

they’re about the best flowing head you can get for a 3.9 bore

better suited for a 383 or high rpm 5.7
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Old Sep 27, 2021 | 03:44 PM
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Bumping this up. Any info on these? Any results?

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Old Sep 29, 2021 | 07:51 PM
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There coming out with so many Knock offs it's hard to keep up.

I'll paint a picture for you...Think of any Mast Knock off or Variation of there LS3 and there's your Data..

SPS, Liberty ls3 heads, hell throw in the Shawn Hooper Armadillo ls3 or the FED m311 vs factory ls3 head's. TSP uses the older tfs 13.5 valve angle of the TFS cathedral head.

Imagine it for the use on a smaller bore...

Most guys will go with a head spoken on or someone referenced, question is who's going to see this as a Plus as a purchase and there Budget...

Speed Masters was a plus for me in Ls7 heads... If the guides & seats are good, buy them bare and purchase the best parts for a given combination. Some heads are thinner in areas but that answer comes from porting ..once you've seen one it's just another head on the market.
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Old Oct 3, 2021 | 05:00 AM
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Originally Posted by Mavn
Bumping this up. Any info on these? Any results?
I'll be using them soon. Boosted application
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Old Oct 4, 2021 | 01:26 AM
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I remember in the PRI video the rep said they were making them for stock bore 5.3's. Any of these work on a bore that small?
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Old Oct 4, 2021 | 08:44 AM
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Originally Posted by jayyyw
I'll be using them soon. Boosted application
You got any pics of them?
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Old Oct 4, 2021 | 10:01 AM
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We leaned on the cathedral 6 bolt version a little this weekend, made good power, no issues with coolant pressure, they wanted a bit lower timing than the TFS heads.
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Old Oct 4, 2021 | 10:17 AM
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You guys Know what's funny.. When I used a Chinese heads for a factory bore and all the Talk about using there casting.

Now it's the in thing from Various manufacturers.

Real talk...I don't Forget
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Old Oct 4, 2021 | 01:10 PM
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Originally Posted by SLOW SEDAN
We leaned on the cathedral 6 bolt version a little this weekend, made good power, no issues with coolant pressure, they wanted a bit lower timing than the TFS heads.
Good info. you order them bare? Or with their valves?
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Old Oct 4, 2021 | 01:55 PM
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Originally Posted by Mavn
Good info. you order them bare? Or with their valves?
Friend got bare units, the shop he bought them from fit nicer valves and springs before delivery. Decks are thicc, pushrods had to be almost an inch longer so went to 3/8" units, hotside had to be adjusted as well due to the height. They use LS3 rockers so used stock ones, but taking it up to 78-7900 had no issues power curve was smooth as can be.
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Old Oct 4, 2021 | 04:13 PM
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Originally Posted by SLOW SEDAN
Friend got bare units, the shop he bought them from fit nicer valves and springs before delivery. Decks are thicc, pushrods had to be almost an inch longer so went to 3/8" units, hotside had to be adjusted as well due to the height. They use LS3 rockers so used stock ones, but taking it up to 78-7900 had no issues power curve was smooth as can be.
Thinking of grabbing a bare pair of the small bore ls3s for a n/a ls1 build. And having valves put into them, blended and valve job done. Maybe do a cleanup of the runners .

They look like an as cast version of the mast small bore 240cc ls3 heads.
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Old Oct 8, 2021 | 01:17 AM
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Originally Posted by Mavn
You got any pics of them?
Should have some next week, i believe.
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Old Oct 8, 2021 | 01:18 AM
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Originally Posted by superfly85
I remember in the PRI video the rep said they were making them for stock bore 5.3's. Any of these work on a bore that small?
I'll be running them on 3.800" bore. Need a little smaller exhaust valve to clear.
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Old Oct 8, 2021 | 12:52 PM
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Originally Posted by jayyyw
I'll be running them on 3.800" bore. Need a little smaller exhaust valve to clear.
You boosting this one?
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