SaLS1

So i have heard ls1 heads ported flow the same as ls6 heads ported. I need some input. I am building a sleeper and i wanted to put ls6 heads on the car but on the ls6 head its stamped 243 on the head.

99Bluz28

iTrader: (35)

If your wanting to totally avoid possibly getting flagged on a smog check I'd have your stock heads cnc ported, and milled slightly to get the SCR up to 11:1. I believe that the LS6 heads will still have a slight potential advantage ofabout 5-10 rwhp.
Fyi, a FAST 92 intake manifold is also 50 State legal and has C.A.R.B. approval/number. So it's a good option .

bane89

iTrader: (3)

Depending on how its ported yes the ls1 241 can flow better. But ls6 heads have alot more potential. They are stamped 243/799.

I wouldn't waste my time on ls1 pre 01 heads to port on .

243/799 are the best to go... 317 if your planning on boost.

Burken01

iTrader: (88)

Shave the 243 symbol off, simple

And 241 and 853 heads are the same.. Just cast differently

SaLS1

I live in chicago so smog isnt a problem. And i have a 01 z28 so those heads are fine. I know the 98-00 heads suck. Also i would shave off the stamp but its a sleeper car. And i know the first thing i look at would be the heads and ppl would know right away if i shave off the stamp. And i have a money maker kit getting installed on my ls6 intake so im not going with a fast intake.

Burken01

iTrader: (88)

I wouldn't worry about 241 vs 243 heads.. It's really a moot point once CNC ported

Set the car up properly and that's how you win a race.. I'm talking gears,converter, suspension..

whatsa347

iTrader: (6)

They're literally the exact same heads, except for some casting numbers. 98 heads have different bolt holes.

SaLS1

The cars gonna be setup really nice. There is alot of kids around the neighborhood with mustangs that have exhaust n they think they are hot **** at stake n shake lol. So imma beat them all pedaling obviously.
Setup:
Ported heads
Gear
Converter
Cam
Full BMR drag suspension
And my fav "The money maker kit"

Leaving stock exhaust n manifolds cause imma try n hide the cam alittle better. And if you know what the money maker kit is....well you know 😉

96capricemgr

iTrader: (1)

Ported 241s are NOT equal to ported 243. Not if you use a good shop anyway. I am sure that some high end 241s compete with low end 243s but that is quality of work not casting potential.

Burken01

iTrader: (88)

Nobody said equal!

96capricemgr

iTrader: (1)

So you didn't use the word equal....

Burken01

iTrader: (88)

The guy obviously street races, a small hp diff won't net him a win in a race.. A properly set up car will..

Maybe I should have used this response earlier

KCS

iTrader: (20)

Rock the 241 heads. They're certainly capable of making good power and they're highly underrated.

BBATCAR

iTrader: (1)

I just finished my "sleeper" and I have to pass emissions. Originally I had a heads only car with 799 Ported heads, the 799 stamp is very hard to locate so I pass inspections. It was much better top end but hurt down low off the line with a stock cam. I thought maybe I should have done ported LS1 heads...

BUT then I put a very mild custom Tick cam in and holy cow!! what a difference!! I'm now glad I went with the LS6/LS2 heads. The car hauls and is a total sleeper, idles very close to stock and passes emissions, all on a stock stall, manifolds and cats. . The car is a blast to drive and the installer was very surprised at the performance. At an intersection you cannot tell it is not stock, total sleeper .

IMO the only reason to stay with LS1 heads is cost and if you are not going to do a cam. But if a cam is ever in the future you will be glad you have the LS6 heads.

Burken01

iTrader: (88)

Exactly, comes down to budget.. The same can be said about going aftermarket heads vs a 243 even

Comes down to how much cash you have

A.R. Shale Targa

iTrader: (2)

I'm guessing that if the OP sent his factory GM castings of "whatever the **** number" to Tony Mamo, Called Martin @ Tick for the "can't hear ****" camshaft, and set his car up to hook on the street with the Money Maker:
The local Mustang kiddies are gonna feel T-Bagged....

newchevyman

iTrader: (15)

Only 02-04 Z06 and 04-05 CTS-Vs have the lightweight sodium filled valves.

dr_whigham

iTrader: (49)

Never a dull piece of advice from you, huh?

joecar

Did you have to pass a smog test or a referee inspection...?

BBATCAR

iTrader: (1)

I had to go to a "Star Certified" station. I can tell you they spend about 15 minutes under the hood with a flashlight. Not sure all they were looking at but it passed visual inspection and smog test.

Someone else I know has heads and 222/222 cam in his GTO and had to go to a Referee and passed no problems.