stg 1 ls6 heads

**Mike0202** · 10-09-2012, 04:56 AM

How much power is to be gained with a set of stg 1 ls6 heads on my setup?

Thanks

**35th-ANV-SS** · 10-10-2012, 04:40 PM

Most people use 243's port & polished for a budget friendly head. Are you buying them new? Ever consider a 243 P&P from someone like AI? Get a cheap set of 243's and send them off?

**Mike0202** · 10-11-2012, 09:06 AM

Okay. Would that be cheaper than buying the heads from tsp? I never buy used parts though.

**Firebirdjones** · 10-11-2012, 09:29 AM

Well you would have to have a set first, to send off to AI,,,and since you don't generally buy used parts (I usually don't either) then it might be easier for you to use a place like Texas Speed. That is unless AI is selling sets done and ready to ship? I don't know.

How much gain are you looking for? Ported LS6's over bone stock heads (what I guess you have?) would see some moderate increases, and you get a bump in compression as well (at least 1/2 point and if milled you gain more).
If you are looking for much larger gains then a quality aftermarket head would be ideal and hard to beat.

**redbird555** · 10-11-2012, 09:42 AM

Originally Posted by Mike0202

Okay. Would that be cheaper than buying the heads from tsp? I never buy used parts though.

I'm not against buying used heads at all but a set of used 243s is around 400. Then the good ai port job will run 1k so your into a set of heads now for around 1400 that have been used plus 200 or so for springs.... A set of stage 2 ls6 heads from tsp with springs and titanium retainers runs 1500 and change. So for basically the same price you will get heads that are new and should make the same or better hp numbers

**Mike0202** · 10-11-2012, 10:53 AM

Sounds good. I am looking for about a 30hp gain. I got 370/370 on a mustang dyno with the clutch slipping. Id like to hit 400 on the same dyno.

**35th-ANV-SS** · 10-11-2012, 07:45 PM

Didn't realize a port & polish ran that much. Holy shit haha.

**Mike0202** · 10-11-2012, 11:38 PM

Originally Posted by 35th-ANV-SS

Didn't realize a port & polish ran that much. Holy shit haha.

Would a set of non ported 243s be worth it? I am leaning towards just buying the ported ls6 heads from tsp.

**Firebirdjones** · 10-12-2012, 04:53 AM

243's are great heads in stock form, better design combustion chamber, also a tighter chamber that will bump compression 1/2 point. It has a better exhaust port which gives you a better IE ratio. A REAL set of 243's (aka LS6) will have light weight sodium filled exhaust valves and light weight hollow stem intake valves.

If they were a real set of LS6 heads, I might go through the trouble of using them in stock form,,,that is after they went to the machine shop for a thorough checkout.

If they are just a 243 casting head I'm not so sure I'd go the the trouble to swap.

In the end I really favor the Texas Speed ported heads with all new parts ready to go. Hard to beat the price.

**Mike0202** · 10-12-2012, 10:12 AM

Originally Posted by Firebirdjones

243's are great heads in stock form, better design combustion chamber, also a tighter chamber that will bump compression 1/2 point. It has a better exhaust port which gives you a better IE ratio. A REAL set of 243's (aka LS6) will have light weight sodium filled exhaust valves and light weight hollow stem intake valves.

If they were a real set of LS6 heads, I might go through the trouble of using them in stock form,,,that is after they went to the machine shop for a thorough checkout.

If they are just a 243 casting head I'm not so sure I'd go the the trouble to swap.

In the end I really favor the Texas Speed ported heads with all new parts ready to go. Hard to beat the price.

Ill order the ls6 heads from tsp. Are there any supporting mods I should add? I already have dual springs, rods, ls2 chain, ported oil pump.

**Firebirdjones** · 10-12-2012, 11:37 AM

Sounds like you are set.

**Mike0202** · 10-12-2012, 01:21 PM

Originally Posted by Firebirdjones

Sounds like you are set.

Okay. I wasnt sure if I needed new injectors, or lifters.
Thx

**Firebirdjones** · 10-12-2012, 01:35 PM

Lifters can be reused. As far as injectors, you would really need to get it up on the dyno after the work is done. Logging the injector duty cycle while tuning should be done, and see if you are maxing the stockers. Usually over 80% is considered taxed, and a larger set might be needed.

Better to wait and see before spending money on something you might not need.

**BrntWS6** · 10-12-2012, 04:05 PM

I had really good results with Texas speeds 2.5 ls6 heads and 231/234 cam. I gained just over 100rwhp on the same dyno with the heads / cam and fast 92.

**Mike0202** · 10-12-2012, 11:46 PM

Originally Posted by BrntWS6

I had really good results with Texas speeds 2.5 ls6 heads and 231/234 cam. I gained just over 100rwhp on the same dyno with the heads / cam and fast 92.

Any guesses on the gains?

**redbird555** · 10-13-2012, 03:51 AM

Originally Posted by Mike0202

Any guesses on the gains?

Well the stage 1 ls6 heads are pretty similar to normal ls6 heads with a mild port so I'd say 20-25whp on a camed ls1. the stage 2.5 i'd put around 25-35whp. I'd do the 2.5's and have them milled to around 59cc (depending on cam size) to give a good bump in compression

**Spikito** · 10-13-2012, 08:14 AM

FBJ, not all true LS6 heads came with the sodium valves, only the later years of the C5 Z06, i think just 03-04....I bought my LS6 heads directly from a guy doing a heads cam swap on his 02 Z06, and mine do not.

They are distinguished by yellow valve springs.

**Mike0202** · 10-13-2012, 09:20 AM

I gained 50rwh from the 228R cam. I thought the gains with the heads would be similiar?

**redbird555** · 10-13-2012, 10:39 AM

Originally Posted by Spikito

FBJ, not all true LS6 heads came with the sodium valves, only the later years of the C5 Z06, i think just 03-04....I bought my LS6 heads directly from a guy doing a heads cam swap on his 02 Z06, and mine do not.

They are distinguished by yellow valve springs.

You are right not all ls6's had sodium valves. However the 02-04 ls6 all did along with the ones in the cts-v. In 02 the z06 went from 385-405hp and the valves were part of the "reason" gm justified it. You cant really go by the spring color as gm used a couple different colors over the years 01 springs were blue most 02-05 ls6 springs were yellow but some oem replacements came in whatever color for example mine came blue. The yellow springs starting in 02 just signified they were for the new higher lift cam gm put into 02-up ls6 motors. The good news is that if your heads are really 02's then you do have the valves. You cant tell just by looking at them though. If you had them next to your stock ls1 valves then you would see the ls6 is slightly taller by .025". The only other way to tell is by putting them on a scale... I boguht my z06 valves seperate from my heads and they came off an 02. When I sat them next to the ls1 valves they were slightly taller and just by picking them up you could tell they were lighter.

Originally Posted by Mike0202

I gained 50rwh from the 228R cam. I thought the gains with the heads would be similiar?

Well dont get caught up in top rwhp numbers. Was the car dynoed on the same dyno before an after the cam swap an was the cam the only thing changed? Just wondering because 50whp is a lot to pick up from a 228. But regardless the heads depending on which you go with will net 20-35whp. However its under the curve where they will shine the heads may not pick up all you were hoping for up top (50whp) but they will dramatically improve the under curve power which is something you can feel driving all the time.

**Spikito** · 10-14-2012, 05:26 PM

my springs weren't painted any particular color, just metal, non sodium valves, I'm PRETTY sure mine came from an O2

I still have the valves and springs if anybody wants them, lol