pianoprodigy

iTrader: (1)

As the title says, how much does the typical cammed LS1 gain from switching from stock LS1 heads to stock LS6 heads?

cbrtrx

iTrader: (2)

10 rwhp

redtail2426

iTrader: (10)

20 rwhp.

transAm-98

iTrader: (1)

i got 30rwhp, with TONS more low end and mid-range. car feels a lot stronger at all rpms. and for as cheap as stock LS6 heads are, it's a pretty good mod if you can;t shell out money for ported heads

black_z

iTrader: (4)

What do stock LS6 heads go for?

cowboysfan

cnc will probably give you 40/45 rwhp so stock I would say 15/20. I would port match atleast, then maybe 20 rwhp. jst my .02

fuerzaws6

1LoudTA

iTrader: (11)

are ls6 heads 241 casting heads? sry to hijack

cbrtrx

iTrader: (2)

not arguing but if stock ls6 heads give you 30rwhp over ls1 heads then how come the latest basic ported ls6 heads are about 35rwhp over stock ls1 heads my ported 5.3 heads gave me 35rwhp over my stock ls6 heads so does that mean that my 5.3 heads would have made 65rwhp over stock ls1 heads, i dont think so

Lithium

iTrader: (47)

15 to 20 sounds about right.

Redneck Z

iTrader: (3)

I've seen some GM stuff saying 10-15.

TheBlurLS1

iTrader: (8)

241's are 2001-2002 ls1 castings. Not sure about 2003-04.

243 is the LS6 casting. Casting expert quote me and set me straight please

s346k

iTrader: (4)

the size of the cam would make a difference as to how much hp/tq you gain, also.

change them on a stock cam vs a t-rex...

gains would be more on a t-rex.

transAm-98

iTrader: (1)

easy hot shot, my car was a 98 so the stock heads flow less than the 2000 up models, meaning i would see more of a gain by switching to LS6 heads (which i did). and in any case, my car has always been tuned on the same dyno so there isn't going to be much variation in the dyno numbers.and my dyno numbers showed me a gain of about 30hp

Michael4034

iTrader: (1)

I'll have my 2002 ls6 heads with the light weight valves for sale by next week for 550 + shipping if anyone is interested. They have rev springs good to .650 lift with about 5000 miles on them. Numbers from these heads and a g5x2ish cam are in my sig.

jason.sabovich

iTrader: (1)

If I'm correct 97-98 heads are the same (perimeter valve cover bolts) and 99-02 heads are the same internally. I've never seen a reference to 00-02 heads flowing better. I could be wrong here, so experts chime in.

Redneck Z

iTrader: (3)

The late model heads flow SLIGHTLY better. They're the same design as the earlier one's only smoother.

GuitsBoy

iTrader: (4)

While generally true, the SPM (semi permanent mold) process creates much smoother castings than normal sand cast heads. The 241's were SPM and are rumored to be worth an extra 5 to 10 HP over the earlier sand cast heads.

jason.sabovich

iTrader: (1)

Interesting, I had no idea the casting was different. Can anyone here chime in on the difference between "243" casting heads? It seems there is a "true" LS6 version with lightweight valves and another version with normal valves that is called an LS6, but is really an LS2 cylinder head. I also read that there are casting differences within LS6 heads. The book I just finished said the heads with the small triangle casting just below each exhaust port are rumored to be worth another 8-10 hp over the regular heads.

GuitsBoy

iTrader: (4)

The ls6 heads have the 243 casting with lightweight sodium filled valves.
The ls2 heads have the 243 casting with regular old stainless valves.
The casting is the same between the two heads, only the valves are different.

As for the triangle on the ls1 heads, that means the ead was made using the SPM process, hence the 8 - 10 HP gain. If i recall correctly, all 241 heads were made using SPM process.

my01camaroz28

iTrader: (15)

I was putting 362 to the wheels with a 216/220 cam, stock heads, bolt ons and headers. I switched to the ls6 heads, 228/228 cam with dual exhaust and put down 422 to the wheels.