Thinking about some heads
Originally Posted by 99blancoSS
My car is a 99. Its a different bore size. I understand the head flows great but what about the fact that the combustion chamber is larger than my bore size. What is the effect there is the question?
What are you talking about with a different bore size? That really has no effect, other than if you were running some monsterous 427 bottom end, then you might be short changing yourself a little with off the shelf heads no matter what you choose. Mine is a '99 as well, and has been bored also, and trust me, these heads WORK. The year of your motor has nothing to do with bore size. All LS1/LS6 bores are identical unless the owner has had the cylinders bored over.
Originally Posted by tim99ws6
What are you talking about with a different bore size? That really has no effect, other than if you were running some monsterous 427 bottom end, then you might be short changing yourself a little with off the shelf heads no matter what you choose. Mine is a '99 as well, and has been bored also, and trust me, these heads WORK. The year of your motor has nothing to do with bore size. All LS1/LS6 bores are identical unless the owner has had the cylinders bored over.
Originally Posted by 99blancoSS
I'm saying that my bore size being a stock 99 bottom end is smaller than the bore size of the combustion chamber of the ls6 head. What is the effect? I was told to stay away from that desparity from a head shop. I know the ls6 head will work but is it optimal as opposed to a head with the same bore size that has been p+p'ed ? Will I loose compression? Will it blow out the gasket? Once again I was told to stay away from differences in that area. That it can cause problems.
Whatever head shop that told you that was misinformed. Do some searching on here, and you'll find that the problem you are referring to is non-existant. As fas as compression, I think there is a sticky at the top of the ls1-ls6 internal engine section that depicts what CC a chamber is with what compression you will have. I think with just slapping on a stock 65cc LS6 head, your compression goes up to 10.5:1
Aren't the LS1 in F-bodies and LS6 from the ZO6 the same shortblock......then wouldnt the heads be designed for the same bore.....I know the cc's may be different....I planned on a set of those LS6 heads in summitt and maybe one of those new crane cams. I want 400 plus like everyone else but NO DRIVEABILITY ISSUES......true daily driver 100 plus miles a day
the block itseld is designed slightly different, but internally, the pistons/rods/crank are all identical ls1 to ls6....that's why i believe it's a misconception of his head shop telling him just because the ls5 heads are not the same CC as his stockers, that he shouldn't run them. Actually, i'd be very leary of any shop that didn't know any better than that, head shop or not.
Kinda funny hearing these so-called professionals saying these heads are for a different bore engine. I have a 346 cubic inch engine stock shortblock with the 60.7 cc GMPP LS6 heads with my gasket I have 11:1 compression. My car through a 12 bolt with 4:10's, a small FM11 camshaft, LS6 intake, Ported stock T.B. With heavy aftermarket 18X10.5 chrome Z06 wheels, full belt with the cutout open made 437/407 with a generic tune. My car has not even been dyno tuned, she's fatter than hell!!!
I believe the TEA rev 2 5.3 heads will still outpower the GMPP heads for less money. The TEA's with a Futral cam would be a killer combination. BTW, the only diffrence between the the 1.5's and the 2's is the exaust valve size. 1.5's use a stock ZO6 exaust valve (1.55) or a simialr 1.55, and the 2's use a 1.57's. Personally for a stock bottom end, I'd go with the 1.5's unless your going to spray, then it would be the 2's. You'd also have killer customer service at TEA. If you have any trouble, there is someone there that will talk it over with you and take care of the problem. Who you gunna call about the GMPP heads if there is trouble? Plus you would have to swap spprings.
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i just got my TEA 5.3 stg 1.5 rev 2 heads in today and the flow sheet said the following:
TEA Flow #'s
lift intake exhaust
.100 70.9 53.8
.200 142.5 119.2
.300 203.8 164.6
.400 250.1 221.2
.500 290.7 245.7
.550 304.6 252.1
.600 315.9 255.3
TEA Flow #'s
lift intake exhaust
.100 70.9 53.8
.200 142.5 119.2
.300 203.8 164.6
.400 250.1 221.2
.500 290.7 245.7
.550 304.6 252.1
.600 315.9 255.3
Thread Starter
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Here's flow numbers for the GMPP heads straight from the horses mouth
Hi, we actually do the CNC work on those heads for GM, let me give you some info:
the heads are made in 2 versions, a 60cc and a 62cc chamber. The 60cc chamber will give you about 11.3:1 compression on a stock bottom end.
Flow numbers:
Int. Exh.
200 150 117
300 225 168
400 273 202
450 285 210
500 291 217
550 304 221
600 311 222
They still use the LS6 sodium filled valves, stock size, and LS6 valvesprings. The 60cc versions have been milled approx. .055" to achieve this chamber size, so you will have to notch the 4 corner bolt recesses to make your intake fit, but it's no big deal. Over all, a very good set of heads for the price considering your getting new, genuine GM LS6 heads, CNC ported for about $1900.00 outright.
Fell free to let me know if I can answer any other questions for you.
Ed
the heads are made in 2 versions, a 60cc and a 62cc chamber. The 60cc chamber will give you about 11.3:1 compression on a stock bottom end.
Flow numbers:
Int. Exh.
200 150 117
300 225 168
400 273 202
450 285 210
500 291 217
550 304 221
600 311 222
They still use the LS6 sodium filled valves, stock size, and LS6 valvesprings. The 60cc versions have been milled approx. .055" to achieve this chamber size, so you will have to notch the 4 corner bolt recesses to make your intake fit, but it's no big deal. Over all, a very good set of heads for the price considering your getting new, genuine GM LS6 heads, CNC ported for about $1900.00 outright.
Fell free to let me know if I can answer any other questions for you.
Ed
Just to be able to compare side-by-side
Not to be bias, but the GMPP head kills the above stated head down low, thus making better power all the way through. People misconcieve all those big peak numbers, but don't realize these heads don't do crap down low. I can say TEA makes some killer heads, but people have also taken these GMPP heads and got 345 @ 600 out of them with a finish polish job and bigger valves.
Where do you get this GMPP head?
ANd to clarify what this person told me aboutr the bore size. Mine is a 3.90 and the ls6 is 4.0 is what he said. He's a trusted member on here so I wont disclos ehis name maybe I read it wrong as to what he was trying to say. I told him I was going to try my own porting until I can afford his heads I asked if I should look for a used ls6 head he said no diff bore, could cause trouble. I'll find the mail and post it. But styill wqhere do I get those heads?
ANd to clarify what this person told me aboutr the bore size. Mine is a 3.90 and the ls6 is 4.0 is what he said. He's a trusted member on here so I wont disclos ehis name maybe I read it wrong as to what he was trying to say. I told him I was going to try my own porting until I can afford his heads I asked if I should look for a used ls6 head he said no diff bore, could cause trouble. I'll find the mail and post it. But styill wqhere do I get those heads?
Originally Posted by tim99ws6
your local dealership, gmpartsdirect, SDPC....etc
And I found the quote:
"LS6 heads will bolt on no problem. You have a 3.90 inch bore. Stay with heads made for that bore if you want them to work well."
Are used ls6 heads the same or is there a year of mfg involved for the good ones. Whats the casting number I should be looking for?
the GMPP LS6 heads that are CNC'd are NOT stock heads. You just can buy them from the dealership. They are a custom CNC job that GM contracted out to LPE. I have independant flow numbers that confirm they will flow beside, if not better than comprable Stage 2 and 3 LS1 heads. The real kicker are these are not hand finished. With a little extra work, you can easily out-flow some big name heads. These heads are NOT mean ot be hooked up with a cam over .600 lift, as they were designed to flow up to .600, but not over. They are a killer combo for either the hotcam, or the ASA cam, as those cams fall directly into the range of these heads flow charecteristics....
940/peice or 695/peice, and the numbers posted are the stock ls6 heads?
Ok those numbers are for the cnc'd ls6 heads. ANd they're not that much better than the 1.5 rev2 tea's in fact they are only better at one lift spec and only 1/100th better while the exaust is considerably less. And they're more expensive than the tea's.. Now maybe with some hand finishing you can get them to flow better but they are still more expensive than the tea 1.5 rev 2.. Did I read the numbers wrong?
Ok those numbers are for the cnc'd ls6 heads. ANd they're not that much better than the 1.5 rev2 tea's in fact they are only better at one lift spec and only 1/100th better while the exaust is considerably less. And they're more expensive than the tea's.. Now maybe with some hand finishing you can get them to flow better but they are still more expensive than the tea 1.5 rev 2.. Did I read the numbers wrong?
Last edited by 99blancoSS; Apr 24, 2005 at 11:07 PM.
Originally Posted by tim99ws6
at what lift spec are you readin from? .600?
Int. Exh. cnc ported ls6
200 150 117
300 225 168
400 273 202
450 285 210
500 291 217
550 304 221
600 311 222
.100 70.9 53.8 TEA 1.5 rev 2
.200 142.5 119.2
.300 203.8 164.6
.400 250.1 221.2
.500 290.7 245.7
.550 304.6 252.1
.600 315.9 255.3
ok it seems the intake is better on the ls6 and exaust is better on the tea's... the ls6 cnc didnt start until .200... threw me when trying to compare them..
but neither is better than the other straight across the board... the tea's are still cheaper. The CNC ported ls6's will cost $2,257.20 delivered. The TEA 1.5 rev2's are $1660 .. big difference
https://secure.gmpartsdirect.com/sec...TOKEN=70364794
Last edited by 99blancoSS; Apr 25, 2005 at 12:08 AM.