1sicss

iTrader: (3)

So I'm currently running the TV2 cam from TSP with all supporting mods which are also in my sig. My question is, is it worth dropping money on stock 243's no porting and bolting them right on my motor will there be a significant power increase over the stock 1998 ls1 castings?

Paul57

I don't know the exact difference but I don't believe it would be "significant". Now if you were talking CNC'd 243's, that would be "significant". Although, what do you consider "signifcant"...20+hp??

99T/AMAN

iTrader: (1)

From what I have read and been told stock 243's are good for about 20hp. I did it on my car.

Damian

iTrader: (89)

If you cut them around .020 to pick up the compression, you'll gain +/- 15-18 HP.

MNJET

If your 1998 heads are casting #241 they are 10.1:1 CR and have port volumes of 200cc intake and 70cc exhaust.

The #243 castings (LS6) have a smaller combustion chamber, raising the CR to 10.5:1. Also the ports are a little larger, 210cc intake and 75cc exhaust.

The compression ratio change will help accross the RPM range while the port volumes will help mainly ath high RPM. How much....I don't know.

ANTICOP RAM AIR

iTrader: (7)

If you already have a cam, those heads should pick you up 50+hp over the stock heads if you also have the ls6 intake... that is on the high side I believe but you can pretty much guarantee 40hp gain... thats whp too...

A.R. Shale Targa

iTrader: (2)

I've read claims of 25 rwhp replacing stock 853/241s w/ valve job/surfaced
243s. But like mentioned some cnc'd 243s will eclipse the 50 mark.

PREDATOR-Z

Be patient, put a nice valve job on with AI, then swap them over and re-tune. Look around to see the true cost of such a swap.

Damian

iTrader: (89)

There is no such thing as a "1998 241 casting". 98 heads are an 806 casting. 241's were not introduced until 2001.

Jimbo1367

AI or TEA CNCd 243s. UNLESS you all ready have 241s. Then its AI w/AI cam

willis b otch

Im in the same boat as you. lol I've been saving up for some head work from TSP

I found a thread on here someone who made just under 400

https://ls1tech.com/forums/generatio...243-heads.html

so I asked the guy this lol



hope this helps..

IRONFIST

If you are wondering if it's "worth it" price wise, here's the break down of what it's going to cost you.
A set of 243 heads shipped $ 500
ARP bolts or studs $160-$250
Cosmetic gaskets $150
And if you're going to mill them for that extra "bump" in compression then you need to factor in the cost of that, plus new push rods which will bump your head swap to something like $1200
I've seen worked over 243's in the for sale section for $1000
It basically breaks down like this
Stock 243 head swap: $900
Milled 243 head swap: $1200
Ported 243 head swap $1400

Not to mention it's going to cost you a weekend of your time either way...
I wish someone had broke it down for me like this before I bolted on my stock 243's.. so I'm doing you a favor. Save a couple extra bucks and get the ported ones as it's really not that much more expensive.

Damian

iTrader: (89)

I'm not sure if prices are more expensive when you live, but that pricing structure is off for US customers.

243's- Seen them as low as $250, and typically go up to $350 for non-Z06 castings. $500 is on the high side, but they can be had for less.
ARP Bolts - $130 for 97-03 blocks, $110 for 04+ blocks. Also, who said ARP bolts are a requirement? The ease of installation is nice, but they're not a necessity. You can get a set of GM bolts for $50.
Gaskets - Who said you needed Cometic gaskets??? GM MLS gaskets work just fine, and are $70 for the pair online.
Pushrods - $86 for Trick Flows through Summit racing.


So, theoretically a 243 swap can be done for $600-700 depending on the parts used and where the person shops to get them.

The only other additional expense I recommend is milling the heads, which can be done for $50-100 depending on the machine shop. This should be mandatory on any aluminum head swap anyway, as the deck surface can get slightly warped from removal. Whether it's just a .005 clean up, or .025 for compression purposes this is a necessity. About a year ago I sold a set of used 243's to a member on here and repeatedly told them via PM to mill the heads for a clean up pass. I probably told this person 5 separate times. He refused to take my advice, and both head gaskets leaked.

For some reason there's never enough time to do it right the first time, but there is somehow always enough time to do it twice.

NemeSS

iTrader: (127)

Ive gone as far as refuse install service for non milled used ls heads. Becuz they will leak. Like Damian mentioned its necssary. No way around it with used aluminum heads.
I always have the heads milled up to .030 for a stock uncut head. And a vj and backcut on the valves for improved performance.this is the minimum amount of wirk required imo for just a stock head swap. Cnc and vendor heads come ready to install. So the price is correct, for no other prep needed

baxsom

iTrader: (6)

you cant count the cost of bolts and gaskets because you will need those anyway. 01 zo6 and 799 heads go on ebay for 300 bucks, average 200-300 to check and clean up.

so in reality i am only paying 500 total for the stock cleaned up 243 heads.

IRONFIST

That may be... things are more expensive in Canada. Basically shipping, gaskets, bolts, and labor ( which is really the most important for myself ), is going to be constant.
If I could go back, I'd wait and get a set of ported/worked over 243's.. It would have cost me $500.00 more which is nothing compared to a lost weekend and misc parts. For guys in the states it might cost $600 or $700 more for some ported 243's.

If you want to cheap out and get regular gaskets, and regular bolts, regular springs, not mill so you won't need push rods, then you might be saving money.
But you're still wasting all your labor and leaving a lot of power on the table. Not to mention that getting a broken head bolt out is not fun ( and I know from experience ).

Its Slo

iTrader: (6)

A friend had his shaved .030 and he picked up 2 tenths in the 1/4. He picked up about 35 hp on the dyno. No porting at all

BADD SS

iTrader: (4)

Here in the NE, $500 is average for 243/799's

Jimbo1367

$500 is way too much IMO. I got low milage 243s with rockers and valve covers for $335 shipped. Remember guys, these heads also come on newer trucks. I found mine through www.car-parts.com

Jimbo1367

I just found these through Car-parts.com. This yard has two heads avail.

2007
Head(Cylinder)
Chevy Truck Avalanche 1500 243 031311 $125 B & F Auto Parts, Inc. USA-FL(Palmetto) Request_Quote 1-941-722-6279 Request_Insurance_Quote