ZMONSTER!

iTrader: (9)

I agree with this right here! You already have 243's with lightweight valves, just get them ported, send them to TSP or patriot.

KB99WS6

iTrader: (6)

Don't have time to send my heads out for a porting. My car has already been at the shop 3-4 weeks, can't hold them up forever. The engines out getting pistons replaced under warrant. Thats what got the ball rolling. I keep sending them more and more parts trying to take advantage of having the engine out and heads off...

1FastBrick

iTrader: (16)

No need to get rid of your 243s Save them for later... No doubt they are a good casting.

KB99WS6

iTrader: (6)

Well, while my engine is out and the heads are off, I can add aftermarket heads @ no additional labor charge. If I am going to get heads the time is now! After I add heads there is no point in keeping my 243's when I can sell them for $400 or so. If I wanted 243's down the road I would just buy another set at the time.

So if I buy ported stage 2.5 LS6 heads direct from TSP, I lose the lightweight vavles though, right? because theirs have Stainless ones, correct? Uggh, the dilemma just keeps piling up, lol.

1FastBrick

iTrader: (16)

My thought was get the 5.3L heads now and finish it up. then send the 243's out later... Then you can try them both and see what you like better....

AaronR

iTrader: (8)

Im not debating there would be little difference between TSP's 5.3 AND 243 heads powerwise.The point is the 243 is a better head when properly ported.Take what you will save in money having the heads already and spend your money to have them ported by someone good.

KB99WS6

iTrader: (6)

Why don't you think TSP's porting process is any good? Im no expert but I've in all the research I've been doing I've seen countless people with their heads with good numbers. Not trying to argue with you, just curious what you base this on.

AaronR

iTrader: (8)

You buy budget heads you get budget power.If your happy with that go for it.

black01_WS6

iTrader: (13)

the ls6 heads have more room for later down the road- bigger cubes. there are quite a few 408's running the 243's.

buy some used aftermarket heads- AFR205's would be pimp. Sell your heads and then come up with 1000-1200 and you would have a bad *** set up

KB99WS6

iTrader: (6)

I've been looking for a good used set ever since I decided to get heads but have come across any good deals...unless you think "Mamofied" AFR 205's for $3000 is a good deal, lol.

hammertime

iTrader: (1)

Apologies to 66duece for picking apart his earlier post

After reading and re-reading this entire thread, this seems to be the most important information here.

Are any of the popular porters addressing these weakness in the porting program run on 5.3 heads? Is there enough material in the short side to leave a comparable port after the CNC work is done? Ditto for the chamber.

Anybody out there who knows cylinders heads willing to discuss Cross Sectional Area and other key differences between the two? Preferably before and after CNC machining...

...and yes, it would be nice to see some side-by-side dyno numbers for 5.3 vs. LS6 heads in the same combo...timeslips even better...

66deuce

iTrader: (1)

no apologies needed..this forum is about people offering their opinions and sharing experiences..
sometimes a heated debate get's people to open up their minds,myself included!

ZMONSTER!

iTrader: (9)

/\Im with this guy. I may have made my choice but Id like to see some hard, confirmable data and reasoning about these heads, rather than the "5.3's rock!" "No way 243's are better!" arguments.
Might be a topic for the advanced engineering tech section.

66deuce

iTrader: (1)

i did say in an earlier post why i think the LS6 head are better..
maybe some else with more knowledge than me can expound on the benefits of the combustion chamber and port shape of the 243s compared to the other LS heads?

1FastBrick

iTrader: (16)

Best to talk to some one like Richard@WCCH He would most likely be the best person to speak with. He did tell me you can not take a 5.3L head as far as 243 head. even something like trying to reshape the combustion chamber could prove to be trouble some... I wanted to have this done on a stock set But He explained it nots worth trying to re-envent the wheel when all you have to do Is get a better wheel...

ls2 bait

iTrader: (11)

you already have headers and a decent clutch right? if not id look into that before you start with the heads.

litemup02

iTrader: (39)

^^Well said

I'd say most of the people here are 99% street car and are just looking for out of the box power..myself included If you have a race car ..and or deep pockets. You want the best because you need it or $ isnt an issue (must be nice) I also have a smaller cam and it seems to be that the popular choice is the 5.3's. And i've been told they like nitrous due to the bump in comp.

On a side note...why is it that a $1200 set of heads flow better than a $2200 set? (AFR's) and i know that they have all kinds of potential for porting..just thought you would get more than that for the money

KB99WS6

iTrader: (6)

yes I am also having a Centerforce DF clutch installed, and I have a Vararam + full exhaust: Dynatech stainless LT's & X-pipe + Borla Stingers. My car dyno'd 377rwhp before the stingers. I am looking to get ~430 rwhp after heads/cam.

litemup02

iTrader: (39)

You should pick up more than that with heads and cam..i'd say 450 ish

66deuce

iTrader: (1)

depends on what flow bench was used,and if the operator fudged the numbers..AFRs have the most honest flow #s out there..most shops inflate their flow #s to sell heads..
and you can't judge a head based on flow #s alone..it's about the quality of airflow,not just quanity..