3 Amazing LS Heads From Promaxx Get Reviewed With Real Flow Numbers

[@robertwest3093]

I love it when you can actually hear the excitement in Eric's voice! You know that the head he is talking about is good!

[@kylejacobs6093]

Kinda looks like they sent you some ringer's. Full Port job with a little sand blasting to hide it the guides fully profiled. Still looks to be a real nice head.

[@Comet-hn3gm]

I have said it multiple times. ProMaxx makes a good product at a fair price and the service has always been Great. Very nice to do business with them.

[@robertwest3093]

They are probably the ONLY budget head that you get your money's worth out of.

[@donavan2676]

ProMaxx does not "make" anything, they just buy and sell.

[@Comet-hn3gm]

@@donavan2676 ok, ProMaxx sells a good product. 🙄

[@mikegillam1000]

They don’t have a foundry, but they do the final machining, valve jobs, assembly, and QC work. They seem to source pretty good hardware, too

[@donavan2676]

@@mikegillam1000 They bump the valve seats with a stone, and check/hone the guides, they send out their CNC work... I am in the industry, I know who does, what, and who buys from who... ProMaxx buys BBC/ LS heads from the same company as FloTek, except on the BBC FloTek puts the 2.300 valve in standard, ProMaxx charges extra for it.

[@TurboDog73TX]

That small bore LS3 style head WITH a factory LS3 intake would be an absolute RIPPER in an average street car build. Good stuff, thanks for taking the time to flow them all Eric.

[@timothyarnott3584]

Hey Eric, Tim here, i'm NOT an LS guy, but WOW, some serious flow, and i really enjoyed ur comparison explanation between the 3..........great vid, just super cool!!!.....TY sir, peace to you!!

[@nowayjose596]

One more thing in the small bore LS3's favor vs the cathedral is that LS3 intakes are relatively cheap and work really well - to get comparable performance out of a cathedral port intake you need to step up to something like a FAST. If you're running a high ram or something it's a moot point but for those of us with hood clearance issues it's something to consider.

[@trailerparkcryptoking5213]

So, the LS3 is a small bore?

[@faustthehammer8706]

Even when they were patriot they were easy to deal with and the heads are great. I have a early set 227 cnc and they make 700+ hp on a 430 cube sbc

[@chrisstavro4698]

You're right. Holdener did a head test on a 408 and the Mast 2.16" LS3 heads made basically the same power as the Dart 2.05" cathedral port heads.

[@mikegillam1000]

I’m really enjoying seeing your perspective of Promaxx change over the past couple of years. I remember when you said you were gonna be sick when the Maxx 200 SBC head did so much better than the Brodix IK it was based on

[@paul8638]

I'm putting a set of the small bore heads on a cam / headers LS1 soon. Now I'm really looking forward to it.

[@ronnieraines3975]

Thanx Eric, learned so much from you. Just to be clear I'm a BBC. Guy. If I didn't know better after listening to this I'd swear I was listening to a LS fanboy. LOL. Thanx for all you do, I know, I know your not a super man!!

[@Fatt-billy.racing]

What i like is that you can order them in a 59 or 63cc . And when i soften the chambers im not losing a lot of compression and having to put a huge dome in to get it to 12 -1

[@georgedreisch2662]

Should be impressive with something along the lines of the Holley High Ram…provided the runners don’t have too much cross section. Would be interesting to juggle rocker ratios, for lift / valve curtain area, while maintaining velocity for the throat diameter.

[@itseithergonnaworkoritaint7852]

Remember, 5.3L and 4.8L have the same bore size with different strokes.

[@WeingartnerRacing]

Ahhhh

[@shitbox82]

For different folks…

[@itseithergonnaworkoritaint7852]

@@shitbox82 Ha!😁

[@utahcountypicazospage5412]

And bored 5.3 with flat tops iron 5.7

[@jasonstormoen]

The Promaxx stuff has come a long way, and their nice for guy on a budget wanting power. I don't run Sb-LS stuff, I'm a conventional-style Sbc Bbc guy, but my buddy's son has an LS 6.0 f3-112 procharger, and we used the Brodix BR 1 13 13.5° 245cc 2.10 int 1.6 exh cathedral port heads on it, and I'm a big fan of them and the combo.

[@DavidB7474]

Check again. they offer gen 1 traditional sbc heads that flow massive numbers!! He tested the 215 pro maxx head on the dyno, it made more than the afr heads. And promaxx offers even bigger heads. Here is the test. kzbin.info/www/bejne/gJm5kmSCl7qiaaMsi=QzaiIEUrky8Gpm-X

[@jasonstormoen]

@@DavidB7474 I know what heads and video you're talking about. I'm not saying their bad stuff. I been watching Eric for at least a few yrs. He does good stuff, I know a couple guys who run his stuff. For some that Promaxx stuff may be considered a good head, but I'm not a fan of AFR or Promaxx. I stick with Brodix castings and Profiler castings. I like the family owned and 100% American made stuff.

[@DavidB7474]

@@jasonstormoen I’m kind of upset dart stopped making cast iron heads. Work still offers the big 230 cc sbc heads. Some old stock of darts are still out there. Sad. You think companies will make stuff forever, but it’s not the case. When you find a company that makes quality it’s really difficult to change brands. Some of us are willing to pay for quality and the name, so I understand.

[@jasonstormoen]

@@DavidB7474 Yeah, It does suck when a company has a good run on something, and they up and stop it. My thing, I may pay a little more for say a Brodix casting with say PSI or PAC springs and Manley Severe Duty valves, but I feel the stuff last long like T&D and Jesel shaft rockers.. Dart has went down a lot, it seems. Back in 99 I had a set of worked over Dart 23° 220's 2.12 int 1.6 exh, but when I sold them curtis turned me to Brodix and I just never looked back. I remember when the theory was Aluminum heads are for racing and not street use. Now Aluminum heads and blocks were doing drag and drive stuff no issue.

[@jeffwooton7138]

Man! I want some of them small bore heads! They would be perfect on my LY6 daily truck!

[@faustthehammer8706]

I mean Over the years a larger port flows more and can achieve more hp but we don't race top end on dirt or anything like that so. A runner sized to provide low end response was always like you pointed out peak hp is nothing peak torque early and throttle response means alot more. Completely agree eric

[@morganpowell2999]

I really like promaxx heads, I’ve used a couple different sets. They do really good work. My only complaint is they don’t put helicoils or anything in the bolt holes. You’re just threading into aluminum.

[@cedricwilson2055]

Shouldn’t need to torque rocker studs that tight to pull threads if heat treat right

[@drivinwithdrew7676]

Loved the reviews and the enthusiasm!

[@jcnpresser]

Kinda crazy, a small block with bigger intake runners than it’s big block brothers. Man I can’t wait to get me some Promaxx heads for my sbf! You sold me on them. I remember when they came out, they were so cheap. Lees money than a cast iron vortex head and flowed better. I was thinking about getting them on my old Chevy short wide back in the day, but ended up selling the truck.

[@cedricwilson2055]

Now think about all the smallest runner for the cubic inch that’s been around forever. GM didn’t get that memo

[@DavidB7474]

They even have gen 1 sbc aluminum heads that flow massive numbers. Massive numbers.

[@davidresar8256]

Thank you for sharing! As always, great video! Keep up the great content!

[@BN-pi3jk]

I have a set of the small bore heads on my hydraulic cam 415, with 40lb of boost, Wallace racing calculators says it's making 1840hp

[@pbadasay]

I have a 6.0 408 ls build that I’m looking to put a kong2650 supercharger on top of…go with the 240 or 260 heads? And why? Ps love your content and thanks for the info!

[@chevyrc3623]

That's awesome my class i wish they would allow LS in circle track but i think there is another wingless sprint car class that is more open on engine rule like no 2 barrol you can run fuel injection. But it would be cool to try out the small bore LS Cathedral on a 6.0 because the cubic inch rule is 360 plus 2 percent which is 367 and the 6.0 is 364. So if i do go ls i will definitely go with those heads if i have the money and have you port them. But now my current engine rule since there is multiple Wingless class mine being spec amd have to run a 2 barrol our rule only allow any iron head iron block engine. So basically we just run sbc but at the end of this season i will get in contact with you again and hopefully to finally send you some stuff sorry it's been taking way to long but just trying to come up with some money.

[@shitbox82]

Intriguing, I have a 370” LQ4 based engine that could make use of the small chamber LS3’s…

[@rolandgutierrez813]

Hey Eric , love your cool videos , thank you so much for taking the time and explaining all the cool tips and tricks about your experience with LS Heads , i am at the point where i am going to build a LS 6.2 , what do you think about Frankenstein Heads ? thanks

[@WeingartnerRacing]

I am thinking you are asking about a head I don’t sell.

[@fbodyfreak4thgengang520]

Will you be doing some dyno testing with any of these heads?

[@LynnTwinCustoms513]

Wish you had a 6.0 or 408 test mule to test on. Be some good content as well

[@WeingartnerRacing]

I’m building one now.

[@LynnTwinCustoms513]

@@WeingartnerRacing nice! I was trying to talk my brother into the promaxx small bore ls3 for his 408 but he went with the Texas speed brawler ls3 heads because they were like 300 bucks cheaper but I feel his combo would benefit from the smaller runners on the promaxx. 408 isn’t going to need all of that ported ls3 head

[@richardmahoney4531]

that port job on the bench - ever see cracking on that sharp ridge ?

[@edpetrocelli2633]

I always if permitted, (rules) run my lifts about .050 above max flow lift simply because the valve stays at or above max flow for a longer amount of time or crankshaft degrees.

[@davidreed6070]

I wonder, if you opened the small bore head to the 6 liter bore size and unshroud it more, what would happen . Eric will you measure the chamber and tell me how wide it is. You have convinced me. Depending on the price

[@WeingartnerRacing]

It’s unshrouded because it’s a smaller valve. No need to open it up.

[@ChrisMcCutcheon-wj2pp]

The factory L94 I believe is what these are casted after, I like the factory casted in Canada, great flowing and running heads

[@WeingartnerRacing]

They are not like any factory head. Factory heads don’t flow close to these.

[@ChrisMcCutcheon-wj2pp]

@@WeingartnerRacing L94 does, LT heads flow even better than L94, great flowing heads from factory

[@chill_chewy]

⁠@@ChrisMcCutcheon-wj2ppfactory lt1 heads flow around 300 cfm @.600 lift These heads flow 338 @.600 lift

[@ChrisMcCutcheon-wj2pp]

@@chill_chewy 600 is the magic number on valve lift on 23° sbc head, all the numbers go up on all heads, L94 heads flow 345 at 500 lift

[@chill_chewy]

@@ChrisMcCutcheon-wj2pp you’re trying to compare a 257-260cc intake port to 240cc intake port on an aftermarket head. A stock ls3 head (821) head flows 310 cfm @ .500 why would an Escalade motor have more cfm? Especially since it doesn’t make peak hp like a ls3 ? 425 vs 401 Ported 823 heads are good for big cubes but not in stock form. And an average lt1 (direct injection) head is about 300 cfm @ .600 They dont need to flow as much stock because they achieved more hp through higher compression but since its direct injection it’s not as dangerous as it used to be. Idk if you have done the research. But either way its interesting how these heads achieve better cfm with a smaller port. Its pretty cool. Im gonna throw them on my 383ci ls1 gto

[@mickeycollins2363]

How does the Promaxx 240 and 245 heads compare to Trickflow 235 and 245x heads?

[@utahcountypicazospage5412]

If you have cathedral port with a head this good why change to ls3 or rec port but if you do that’s a win to as that small bore parties 60-80 rear wheel could be done with these

[@Simple_Youtube]

I have to stick with TFS because of the CARB EO... I wonder if Promax will get CARB certified for California

[@gordocarbo]

What are you doing about the latest smog bs? Stock tune is mandatory even trans. They can tell if its been flashed back to stock too Such bs...weeks before pulling my 02 5.3 out and stroking it. Probably good I didnt as it was stolen 2 mos later

[@richardcoleman9645]

Any way we could get about a close price range of that set of heads?

[@GrandPitoVic]

Hey brother, what do you think about the stock intake hollow stem valves on the 821 heads. I bought a pair of low mileage bare used heads for $300. I'm not building a race engine. Burnouts and ice cream. Ls3/6L80 swap in a 03'Crown Vic Police Interceptor. A toy for my wife and myself. Just a cam. Maybe 400-450 wheel. Btr .660 double valve springs. I've heard they like to snap off the tulip and destroy the engine. I can't spe d alot of money but I don't want garbage either. I seen you taking about the hollow stems. It will see some red lining sometimes. I'm not trying to join Street Outlaws is what I'm saying lol.

[@jtartaglia002]

would love to try these on my lsa zl1 but im afraid of the 63cc chamber being too small. stock is 69cc the compression might to to high or the valves could hit.

[@troy8940]

Your recommendation is sounding great for my applications but I didn't quite hear the model in which you was referring to. You were pointing to cylinder head in the middle speaking very highly of it could you please tell me the model. I wanna put them on a 6 .0,(Lq9) Create motor with sloppy stage 2 Elgin cam and a fast intake.

[@williamstel9330]

Sounds like we don't even want to touch a Liberty head for anything.

[@bfromthed]

Being 11* you'll have to modify an existing intake to work with them. They seem like they would be worth it though.

[@WeingartnerRacing]

No. The valve angle is 11degree the intake face is the same as stock. All standard Ls 3 intakes and headers work.

[@timothybayliss6680]

Think the ls3 heads are big wait until a lt1 head gets in your shop...they flow 320cfm and are 297cc. The ports are HUGE. Edit..they have the same head bolt pattern but flipped and splayed valves. I dont know if they work with a ls bore plate

[@user-vy5iu4qd8f]

Has anyone used the Promax heads with promax supplied valves, are they good quality?, do you think they would hold up to 600+ hp all motor engine, love the videos watch them all the time 👍

[@WeingartnerRacing]

Well since that is what was used on the dyno I would say they can easily take 600hp.

[@Fatt-billy.racing]

I have that 6.0 i will pull of my mustang for you to use. It has mast cam and super victor with dominator carb on it

[@smilsmff]

Wish you showed the HEMI 6.2 flow along with these

[@WeingartnerRacing]

Probably

[@lcxu1051]

Are the exhaust ports in the standard location as ls1 2 and 6 on the small bore 240 heads???

[@2manyhobbiezz]

If you have a 15 degree head and an 11 degree head with fairly close flow numbers would the 11 degree head still make more power?

[@WeingartnerRacing]

Too many variables to answer that.

[@2manyhobbiezz]

@@WeingartnerRacing I guess what I mean to say is there gains to be had with an 11 or 12 degree ls3 head over a 15 degree ls3 that already flows well.

[@russelljackson7034]

Right on

[@jcsgarage8052]

Someone should slow motion air/mix being blown through the intake

[@jakeblack4095]

Are there any "big boy" LS guys?

[@CLEEPER1]

Eric do you check out the heads you sell or do they come straight from promaxx? Have a friend interested in the small bore ls3 for a lsa build

[@WeingartnerRacing]

Two options. One is sold exactly as they come from promaxx except I flow one cylinder. Option two costs more which is me checking out the heads and flowing one cylinder

[@joeyjojojr.shabadoo915]

In your opinion, are those small bore 240 or 245 heads too much cylinder head for a 313cu/5.1L ? (3.905" Bore x 3.268" Stroke) .... essentially taking an iron block out to LS1/6 overbore with a 4.8L Crankshaft. The build would be for a lightweight 5speed cruiser (single cab Colorado truck). Thinking roughly .650 lift & 225 Duration close LSA camshaft, 7000 RPM max.

[@WeingartnerRacing]

Yes too much

[@BassorDie]

Anyone put these on a 416 stroker ls3.... thoughts?

[@user-jl4wg9de7l]

Would you put the smaller heads on a small cam 376 block?

[@WeingartnerRacing]

Yes

[@MrKawa74]

Min CSArea, Port Lenght and Valve Seat Angle ??

[@lcxu1051]

Hi Eric. What is the average air flow volisity through the small bore 240 head?

[@WeingartnerRacing]

You can calculate that but I’m not going to.

[@JuanHernandez-uk3so]

Would you recommend the 240cc for a ls3 thats running low 10.1s, 7400 rpm? Currently on unported stock ls3 heads.

[@WeingartnerRacing]

Yes

[@evcass69]

How can I obtain the tech specs on these heads? Chamber cc, port ccs, mcsa, centerline lengths, valve sizes, valve weights, etc, to model?

[@WeingartnerRacing]

I gave most of that in the video. I guess but a set an measure.

[@justinschmidt9180]

Why do LS heads kinda remind me of a small nlock ford head

[@FORCFED]

How much for a pair of LS3 small bore , fully assembled hydraulic Cam? Thanks

[@WeingartnerRacing]

It’s best to email me because how much lift and do you want titanium retainers play a factor.

[@richardsalazar17]

cool

[@visforvendetta910]

do you think it would perform better than heads on an lsa?

[@WeingartnerRacing]

Yea

[@user-zd9ex2bn7q]

Have you flow tested the cnc bbc schoker head from promax

[@WeingartnerRacing]

No

[@user-zd9ex2bn7q]

@@WeingartnerRacing would you like to see a set? I'm planning to remove mine for winter check soon.maybe do fresh up and evaluate if you have any interest.

[@____MC____]

What do you do when you find a casting pit in the exaust port?

[@WeingartnerRacing]

Nothing unless there is a hole.

[@____MC____]

@WeingartnerRacing thanks for the response. Ill keep that in mind in the future. Unfortunately, i took a dremel to it the other day. It was small but it was 1/16- 1/8" deep. I feathered it out with plans of brazing it or welding it. I was worried carbon would build up in it and melt a hole through it.

[@gordocarbo]

@@____MC____ Nah, leave it be. Youd be surprised what kind of visual defects have no real effect on flow/power

[@____MC____]

@@gordocarbo it was deep. I was worried for water leaks more than anything.

[@martygrajeda3457]

How would they handle boost?

[@WeingartnerRacing]

yes better than stock heads.

[@davidcallahan5157]

Can we buy these heads through you ? How much!

[@WeingartnerRacing]

Yes you can. I sell them. Price depends on how you want them set up.

[@xozindustries7451]

Are those the same as the engine quest heads?

[@WeingartnerRacing]

No

[@gordocarbo]

@@WeingartnerRacing Was it promaxx or flotek that was ripping off the afr port design? Cant tell whats what anymore.

[@Boostismyfriend]

4.8 is the same bore as a 5.3

[@WeingartnerRacing]

Thank you

[@joecunic3708]

So the promax out flowes the afr 245 out the box price not much different

[@WeingartnerRacing]

No it doesn’t

[@joecunic3708]

@WeingartnerRacing ok I was watching your other video of the art 245 I thought they flowed less I must of been watching different heads you flowed

[@WeingartnerRacing]

@@joecunic3708 the ls3 heads I flowed and they were better. The Ls 245 or afr I have not flowed. I have flowed the sbc 245

[@joecunic3708]

I watched alot of your videos love your work I must of got them mixed up

[@martygrajeda3457]

What is the cost?

[@WeingartnerRacing]

depends on options

[@martygrajeda3457]

Building a 408 stroker Ls with twin 7875 turbos.

[@2ndAmendProtector]

How much $$$ are the cathedral heads that will fit a 4.030" bore 6.0L LY6 iron blocked 390ci? Is there a CNC program for them yet to port them? Or a link to the manufacturer?