hey guys do ls6 heads really flow that much better than ls1 heads???

 

Yes from what I have seen in flow numbers. Much better for bigger motors. Ls1 heads will work too just not as well. All depends on your end goal.

 

Depends on who ported them. Unported LS6 are about 15cfm extra.

 

so it's not really worth replacing ls1 heads with ls6, just go with ported ls1 heads???? or is it worth it?

 

you wouldn't gain a whole lot from just changing to the ls6 heads without porting. I would just get the 5.7 heads ported

 

Well the LS6 castings flow better, have better velocity, and different combustion chambers, also I believe the runner shape is slightly different.

When choosing a head, it is more important to look at mid lift flow #'s than peak.
.250>.300>.400

since this is where the power needs to be made. So ideally you match your cam specs to the heads potential at mid lifts and avoid potential choking or worse over porting situations.

 

ok well iam running a 224,224 cam wich is good from like 1.5k to like 6k a good enough mid cam would that be good with ls6 heads or just go with ported ls1 heads. The reason i am asking is because i saw some pretty cheap ls6 heads for sale, so i wanted to know if i should go for them or save little and get ported ls1 heads???

edit:: i wouldn't want to waist my time and money on ls6 heads if iam not going to see or feel any difference you know

 

Let me put it this way:

LS1 stage II good
LS6 stage II better, but true LS6 castings "243"

 

ok how about more like ls1 stage II good
ls6 stage nothing ????

 

??????

 

I think Predator is trying to tell you that even ported LS1 heads can't make the same power potential as LS6 heads. I (we) aren't saying that ported LS1 heads aren't going to be better than STOCK LS6 heads. What we are saying is, stock for stock, LS6 heads are at least 20 horses better than stock LS1 heads. And if you were to port both, LS6 heads are going to be better still. Check out LPE's web site on this. They say that on all their engine packages, head porting, etc., that "LS6 numbers will be higher". If you are going to pay a good head porter big bucks to port heads, it would seem that it would cost the same high dollar to port either head (LS1 or LS6), so if the funds are there, it would be better to port LS6 heads. This is one reason that everyone has been anxiously awaiting the AFR heads. By the time you spend $1,200.00-$1,500.00 on a set of LS6 heads, and this is the going rate, about, for the castings Predator is talking about (Not re-worked castings off a truck engine or wherever they get them),and another grand or so for porting, CNC-ing, etc., you got $2,500.00 or so in them. The AFR's are about $2,000.00 or so and should outperform the ported versions of either (LS1 & LS6) for less $$. Sure, you can find used LS6 heads for less, on Ebay or someplace, but you are still going to have at least $800.00 to a thousand bucks in a good set. However, I expect the price of LS6 heads to nosedive after the AFR heads are released in bulk quantities, so if you can wait it out for 3 months or so, you may save a good amount on these heads.Time will tell.

 

zamboxl, get a hold of those ls6 heads for a good price and send them to TEA. Ask for the Stage 2.5 setup. They will kick serious ***.
But then again AFR's will cost you the same in the end.

 

If you plan on sticking with the 224 cam, I would suggest MTI stage 2E 5.3 High CR heads, they are pimp for a cam that size.

 

cool thanks for all the help and input guys i think i'll just wait a little bit, save some money and go with the afr or some other ported ls6 heads. But i guess it wouldn't hurt to check out the 5.3 heads also.

 

I thought TEA no longer existed?

 

I don't claim to be an expert by any means.
I read an article in an old issue of GMHTP where they compared ARE ported LS1 heads to (I think) ported LS6 heads and the LS1 heads actually outflowed the LS6's up until around .350" lift. It was after that the LS6 heads took over but still the difference was minimal. You're going to be driving the car at low to mid lift most the time unless this is a track only car so like Predator said, those numbers are going to be of more importance.This is also mentioed in the article.
This was an 00" or 01" issue so maybe things have changed since then in the world of LS1 heads. Like I said I'm no expert.
I am also in the process of researching heads/cam for my 01 SS.

I'll see if I can find the article if you like.

BTW, GM parts direct sells a set of CNC ported LS6 heads for around $922ea.
GM PART # 88958622
From what I understand these are milled .055 so you will have to be careful on cam selection and check your valvetrain geometry. I was told they also sell a set of ported ls6 heads which are not milled but I don't know the part no. offhand.

 

Yes but GMPD will charge you like $300+ bucks for shipping!

Fred Bean Pontiac will charge $55. That's where I'd get them. Do they offer this head W/O the valves and springs?

 

I am replying to this because i like finding info that is usefull, so i want to contribute. My experience with LS6 vs.Ls1 heads is that when both are ported to competitive flow levels, the LS6 head flows around 20 cfm higher with intake bolted on for flow testing. This is important consideration. If i had to answer why, i would say port width on LS6 head is larger than Ls1 casting is capable in short side turn area. LS6 intake compliments this width of intake port, as they were designed together. My own personal next step will be to r+d 6.0 head port to flow LS6 ported #'s with close to stock port volume size. Using stock valve sizes this will give me excellent power with same med. size cam and no AFR or GM CNC LS6 price tag.( I am completely impressed with AFR heads just no money on my end BTW) As for getting compression back i will shave 6.0 heads around .060" and set PTV clearance as needed.
I hope this helps, i believe im on right track.

 

at what lift range was the LS6 better, throughout or just ~.500+?

are you the same "LSonederfull" as "LS1derfull"?

 

Jerami, yes i am same LS1derfull, my password info is packed away with my home furniture etc.(moved to South Carolina) To answer your question, 10 cfm at low lifts up to 20 cfm at .600"lift is what LS6 head has over LS1 both with same LS6 manifold bolted to heads.