PowerTalk

Ive heard two different stories with putting LS2 243 heads onto a LS1 with stock 853 heads.

First one is that they bolt onto an LS1 block fine with no issues.
Second one is that they have a different bolt pattern and dont line up?!?

So who is correct?

The other thing, is the only difference between them is the sodium filled valves in the LS6 243s!?

I have searched but have still see both things written

Thanks

bluebird00

iTrader: (9)

the ls2s should bolt right up to a ls1 block,cause im getting ready to install a set on my ls1.

PowerTalk

Perfect

Can you give us some feedback when you're done?

s/c'd cav

iTrader: (10)

only thing i know different is the rocker covers on early LS motors are perimeter bolt and newer are center bolt(LS2)

and the head bolt heights are different on a couple bolts

PowerTalk

I wonder whether people are getting confused about valve cover bolts instead of head bolts?

thegroup

iTrader: (1)

after 1999 (i think), the vavle covers went to center bolts b/c my 2000 has them. i honestly dont know about the bolt pattern but everything ive seen on the net, any LS-series will interchange with the others. dont quote me on it though

Pro52R

iTrader: (15)

Geezus christ..

a search could have saved some bandwith

PowerTalk

I did

There's conflicting answers if you search!

cabech984

iTrader: (11)

The heads will work on your engine. However, if you have perimeter valve covers, youll need to switch to centerbolt covers and their coil packs & brackets. If replacing head bolts, get the ones for your style of engine block because they made different styles for different engine blocks. A set of ARP Head Bolts(6 point) for an LS1 Fbody(or 97-03 LS1/LS6) blocks will cost you $150 from most of the vendors.

That is what you need to know.

NemeSS

iTrader: (127)

ls2 heads will bolt to ls1
only 02-04 zo6 came with sodium filled valves
243 are found on many cars, not limited to ls2
2.00 intake valve 210cc runner
1.55 exhaust valve
D shaped exhaust ports
65cc chamber

PowerTalk

Thanks guys

jsteele90

iTrader: (13)

how can you tell what year 243 heads you have

Summerwolf

iTrader: (3)

I swapped 2006 GTO heads (243) onto my 2004 GTO (241) without any issues whatsoever.

redtail2426

iTrader: (10)

they are on my ls1,no issues.As long as you have centerbolt valve covers now then its a direct swap.if not you will just have to get a set of centerbolt valve covers and the coil pack hardware.

FiredUpZ28

are you guys putting these heads on as they came stock or are they getting ported first?

ls1jorge

iTrader: (5)

Srry to bring up a old thread, but I'm in the process of buying stock 243s, how much of a gain would it be over the 853 stock heads??

bayer-z28

iTrader: (14)

^ Maybe 15hp. 853's are pretty much the bottom of the barrel. I've got an old set hanging around.

ls1jorge

iTrader: (5)

Yea how much you want for 243? & complete??

bayer-z28

iTrader: (14)

^ They're stocker 853's.. not worth much. Was asking $175, but I could prolly get that by selling em for scrap metal. They're as good as a paperweight, IMO. You can get 241's for the same price and a slightly better head. Yeah, they're complete.

You looking for a budget build? I got my P+P'd 243's off an 04 ZO6 for $600 new and assembled, but with stock springs.

jimmyblue

iTrader: (11)

That's what's on mine - home ported GTO (LS2) heads.
No prob.