ZMONSTER!

iTrader: (9)

/\thing is almost everyone running the 5.3's is happy with em. I know I am and I havent read about anyone not being satisfied.
The PRC 243 and 5.3's are 6 to one half dozen to the other, get either one and youll be happy. If you want to spend more money step up to a pair of trickflow's.

66deuce

iTrader: (1)

exactly..

Bad Blue WS6

iTrader: (41)

i hear ya im a noob,,at the H/C stuff, i am very much a noob. I'll get it figured out at some point.

KB99WS6

iTrader: (6)

Well here's the thing....I have heard several people say, and not just in this thread, that the LS6 heads are simply better heads and that TSP & other vendors want to push the 5.3's because they make so much more profit on them. Now this does seem to make perfect sense to me and is something I have strongly considered. However, as Zmonster pointed out, it seems everyone is always happy with their results with the 5.3 heads, and the real dilemma is I haven't seen any real world comparison's of the SAME setup with a swap between ported 5.3's and similarly ported 243's. And that is what makes the decision so hard. I have not been able to find any hard evidence to indicate if in fact the LS6 heads would be superior with a 228R or similar cam. Only conjecture and opinions.

litemup02

iTrader: (39)

Maybe we just need the AFR's or Trickflows to be sold for $1200 That would solve our problem Group purchase! Though we would prob. have to get 2000 people lined up for that

1FastBrick

iTrader: (16)

Well said! If you look at the heads from a stock stand point on a flow bench you see what a 10 cfm difference??? Correct me if I am wrong on that.

Once you start porting and re working the bowls That all goes out the window. As stated before we haven't heard any complaints about guys using the ported 5.3L Head. I don't personally believe you will see that much better results for the Few extra $$$ I think the extra money could be better put to use eslewere.... Also I think all in all it would be more responsive with the 5.3L heads for a street type application....


My .02 worth

AaronR

iTrader: (8)

The 243 has material in the right places to be significantly better when properly ported.When your talking budget heads though and the end goal is a dyno number the difference is probably marginal at best.

ZMONSTER!

iTrader: (9)

Well the accepted wisdom around here seems to be that the 5.3's are better for torque and under curve power, the 243's make more up top, and a well done over set of 241's are right in the middle.
I dont really know how true that is, I mean if you put the same type of CNC program on a 243 and a 5.3 I think the results would be damn near the same. Anyway thats what I think...
BUT using the accepted wisdom of the forum here it would seem that the 228R would go better with the 5.3 than the 243, as they are both suited better to the low end.

AaronR

iTrader: (8)

The accepted wisdom around here is bullshit.How many competitve lsx cars at any level do you see running 5.3 heads?Does GM use them in any class requiring a stock casting?

studderin

iTrader: (28)

if you happy doing heads and cam install to make 420-440 whp then these buget heads sound like the setup for you.

ZMONSTER!

iTrader: (9)

probably not, but where does GM even run an LS1 anymore?
and Im pretty sure that the heads/motor in the c5r were about as far away from stock as possible. I could be wrong, but dosent seem like it to me.

For a 420-450rwhp goal there is nothing wrong with the 5.3's. People might not like them, and there are in fact better heads out there, but something that no one here can deny is that the 5.3's have made some serious power/track times for what they are. Would they be so popular if they didnt work? Probably not. TSP has a lot of influence on this site but not enough to make up for a crap product, ie if the 5.3's sucked as badly as some here would have you believe then no one would be running them regardless of what TSP said.
OP your going to be happy with either one. Both will make good power. Predator Z wont leave you hanging!

KB99WS6

iTrader: (6)

Ok, these people that are saying a ported LS6 head would be much better....honestly what are or what would be the REAL WORLD advantages of say the PRC stage 2.5 LS6 heads over the stage 2.5 5.3 heads with a 228r cam? What are we talking here, 5hp more peak power? What about the power under the curve? what kind of difference? What kind of difference in drive-ability and/or reliability? I'm being serious here, not sarcastic.

1FastBrick

iTrader: (16)

I would venture to say there thinking more along the lines of extracting every last HP out of the combo Vs. real word advantages and so on that your looking for. Predator-Z had some good info in your other thread about Heads.

As far as the heads you may be able to port the 243's further then a 5.3L casting but what good does that do if your engine package can't utilize it???

66deuce

iTrader: (1)

the LS6 heads are a superior casting,hands down..don't believe all the crap that you hear on this forum...if your looking for X amount of power and the 5.3 heads can do that you,go for it..
no doubt you can make some good #s with the 5.3 heads..but properly ported,the 243 heads will out perform any other OEM head,low end TQ and top end HP,it doesn't matter..real world results won't be found on this forum..it's only a small example of what is going on in the LSX world..

ZMONSTER!

iTrader: (9)

well what have you got in the way of proof? Im sure the OP would like to see some firm numbers regarding the various heads.

66deuce

iTrader: (1)

unfortunately i don't have proof as far as dyno sheets or links to other sites..although you will probably find more info on LS1GTO.com,or even hardcorels1.com..
my experience has been at the dragstrip and dyno days over the years..met and raced guys with LS6 heads,both ported and stock..plus i ran ported 5.3 heads on my old Z/28..
not trying to knock the 5.3 heads..good bang for the buck.my point is the OP already has 243s,so why not use them?your starting out with a superior casting..even with just a good VJ and bowl blend you'll make as much, if not more, power than a ported 5.3 head..
one guy i raced ran a set of 243s and a 224 cam that ran high 11s with crappy 60' times due to traction issues off the line.the heads just had a VJ and bowl blend,milled to get about 11-1 CR..3.23 gears and a 3000 stall,if i remember right..it wasn't a big verter by no means..real street car with no weight reduction..
just my .02,take it for what it's worth..

66deuce

iTrader: (1)

found a post on LS1GTO.com..04 GTO,GMPP LS6 heads,65cc combustion chambers,220/224 cam..made 405/385 on a mustang dyno..350ft lbs at 3000rpms..this with catted LTs..in the dyno section do a search under "Edc baby cam" and you'll find the dyno graph..

KB99WS6

iTrader: (6)

And you don't think the stage 2.5 5.3's would make very similar power? Also, thats one post. I've found tons of of posts touting great results of the 5.3's and a small to mid size cam. What we really need here is a swap from one head to the other in the same combo on the same dyno or even better 1/4 miles numbers @ the same track to make any kind of reasonable comparison.

66deuce

iTrader: (1)

true,it's only one post..but my point is you already have a good casting,why not just have someone port it for you?
like i said,not trying to bash the 5,3s,just IMO you'll be happier with the 243s..like i said,in my experience,they are a better head..
but in the end,buy what ever meets your goals and makes you happy..

KB99WS6

iTrader: (6)

Yeah I hear you and I'd prefer to just have mine ported as it would be much easier and than I don't have to worry about reselling mine etc....and thats what I originally inquired about to Dennis @ the Vette Doctors, but he said it would be pretty expensive for their machine shop to port & polish them and I'd be better off just buying new ones already CNC'd and than selling mine off. Thats when I started looking at the PRC heads from TSP which is where I bought my cam kit. And since I just bought the cam kit from them I am assuming they will give me a discount on the heads the same as if I bought their heads/cam package. Originally i just was looking at their LS6 heads, but than Predator_Z said the 5.3's would be best with my 228R cam. When I saw those heads are $300 cheaper, I was like great. Than I did searches and saw those heads make some nice numbers with a 228r and similar cams. But on the other side of things there is a lot of people saying the LS6 heads is a much better casting...and I almost feel guilty getting rid of my Z06 heads for truck heads, lol. But again, it seems the results are very strong from the 5.3 + 228R combo and that I would gain ~30rwhp swapping out my 243 stockers for them. ITS QUITE THE DILEMMA!