98RedBird

iTrader: (77)

Pulled the 347 out of the Camaro and am going with a 408 with spray. I've been researching on which head that I want to go with and I keep seeing tons of praise coming out of the L92 heads. I was wondering how good they are as compared to an aftermarket cast such as AFR or TFS heads. I've also noticed that they run quite a bit cheaper as well.

Thanks in advance for the info!

SLOWWZ28

iTrader: (1)

Read an article in gmht that l92 heads flow great up there with all the aftermarket heads, but have not seen any info on how they will hold up to lifting or pushing water in fi or big shot aps.

COPO9560

The intake flow numbers on the L92 heads look very good, a little challanged on the exhaust side. Kind of remind me of old BBC 840 heads in this regard.

When ported by good shop, numbers published here are quite impressive. Cost goes up accordingly expecially with good valves and springs but still look like a good purchase.

My only apprehension right now is there are not a lot of intake options - suspect this will change in next year or so.

daschra79

iTrader: (2)

They are a great head for the price. I am going to be running them on my new setup. One of the drawbacks are that they have a thin deck and aren't going to hold up to a lot of boost or a ton of nitrous. For a N/A setup they are hard to beat .

caindo

iTrader: (4)

ls3s are doing better in regards to lifting

02 BLK WS6

iTrader: (11)

L92 heads lift under moderate boost, even when o-ringed.

smok'nZ

iTrader: (160)

i think veee8 went 8's with them on his turbo car

redsap05

Biggest draw back to l92 heads is the ptv clearance. Another probelm is the intake runner is was to big for stock cubes at around 260cc. The aftermarket castings like tfs, prc, etp are all better. With that said l92 heads are inexpensive, dont need to be ported but do benefit from a valve job and milling about .030 off if you dont mind flycutting another nice thing is that they dont require an overpriced way to expensive fast intake. The stock Ls3 intake is only like 275 bucks and its hard to beat.

cutlass_455

iTrader: (2)

You say the intake runner is too big??...is this in reference to engine size?? I think most with 402/408 setups would like this size wouldnt they??

Also, LS9 heads have similar ports and a stronger deck (its already supercharged and can take the abuse)

66deuce

iTrader: (1)

the intake runner is NOT too big,you just have to cam it right..
search around this site and LS2GTO.com and you'll find examples of 6.0 motors making plenty of HP and low end TQ with these heads..

Beau@SDPC

iTrader: (14)

I guess the intake runner is just to big for 376 CI? or even 364CI? IM pretty sure there are quite a few gm engines running around with them on there. They will work VERY well for your setup on the 408. Added to the fact that you would not have to flycut any aftermarket piston because they would come with valve reliefs. For the price, we offer the stockers at 450 fully assembled in L92 form, 575 in LS3 form, or cncd with manley stainless valves, patriot extreme spring kit for $1500. Hard to beat that.

66deuce

iTrader: (1)

it cracks me up when i hear people say the runners are too big..another internet myth that need to die.. they put them in big heavy SUVs (and the Vette),no problems with low end power there..
that's a hell of a deal on those heads..might have to buy myself a late Christmas present

redsap05

Well let me rephrase that. The intake runner is not "ideal". However, with that said you do have a point because they do make good power. Is it a internet myth? Probobly. Another internet myth is that you need a big split cam with the heads. I shouldnt talk to loud becasue Iam probobly putting them on my car. The savings with them is to hard to ignore. Once I sell my ls2 intake and stock heads the cost is almost a wash. The only thing I dont like is the flycutting. Even though Iam not going to deep at .060. The same heads and cam combo Iam doing makes around 525rwhp on a m6 ls3 car So with my stalled auto Iam hoping to see around 470 rwhp when we lock the converter on the dyno.

airflowdevelop

Internet myth or illusion...the intake ports are not TOO BIG.

WKMCD

iTrader: (2)

But I read on the interweb.....

sixt9er

iTrader: (2)

This is the first time that I read about about the intake being "too big" or not "ideal". I believe that GM nailed the intake runner on this particular head, as a result, you see the "impressive" (to me at least) flow numbers that the intake runners generate in stock form. I do have to say that in stock form, the EXHAUST runners don't flow the numbers for a lot of people. If one is to do a HI-POWER, N/A engine with these L92/LS3 heads, port the exhaust for maximum efficiency...just my thoughts/input...

mike c.

iTrader: (1)

this is how I see it. My old ls1 set up made 416hp with stock cnc ported ls1 heads from a sponsor and a 232/236 cam. I then added afr 205cc heads and a 236/244 cam both on a 112 lob and went to 463hp on the same dyno. Most of the gain was the heads. I also went from 11.7 na to 11.1 na. The l92 heads are great for a low cost,you cant go wrong. But My bud makes the same power in his trick flow 215 head, 383ci with a non ported intake and crap short headers as my 402ci does with the ported l92 heads and all the best parts to match. The trick flow is the head to have if you have the money. The velosity and design is much better over a stock casting head. They will add some more power and alot more in the torque over the l92. Just my thought.

Beau@SDPC

iTrader: (14)

you do not have to fly cut unless the person building your cam does not know what is going on.

this is on a stock LS2, so there is def something wrong with your combo.
https://ls1tech.com/forums/dynamomet...p-446rwtq.html

looks like 2 more myths are busted.

KCS

iTrader: (20)

Why do you think that?

mike c.

iTrader: (1)

That was all on ls1 stock motor, 463HP. My ls2 motor 402ci,with l92 heads made 517hp cutout open and 495 cutout closed. My buds 383ci made almost as much power but more tq. and,when he ports his fast and removes the short headers for some kooks or something better he WILL pass me up in power and tq. As I said for the cash the l92's are a great head and do produce. but,if you want all you can get,the T.F.S. heads will add more.