I found a nice set of 243 off a 06 LS2 GTO and my qeustion is what is needed to swap them out . Before the heads go on I'm gonna swap the rockers for 1.7 and do different springs . My qeustion Is about what push rods will I need and thickness head gasket . I will be doing a came while it ripped down but that another ? that I won't annoy for a answer at this time . Has anyone swapped the 243 on to a LQ9 and how was the results.y mods are as follows : Dynatech LT with cats, Gibson cat back, flexalite 282 twin fans , Trickflow UD pully W/ over for alt, P&P BBK 80mm TB, taylor 409 wires, yank2600 stall,FLT lvl 5 4l65,410 gears W/ eaton posi,K&N intake and Nelson tune. Sorry for the long ? I just figured the more u know about what I got the better u can help to answery ? about putting the heads on. Thanx in advance!

 

The normal head swap stuff. Stock head gaskets, head bolts, if your doing a cam get some hardened push rods. Also might need a new timing cover gasket, water pump gaskets, timing cover seal,crank bolt.
The 243s will raise the compression to alittle over 10.3:1 I believe. A 224/224 112 LSA cam would be perfect IMO.

 

I'd bet your static c/r would be closer to 11:1. High 10's anyway depending on head gasket. I'd use stock GM LS2 gaskets. You have 1.7 rocker arms now. Use them unless you have a serious wad of money burning a hole in your pocket. Have Pat G spec you a cam, springs, and p'rods. Retune. Enjoy

 

When u say I have 1.7 now do the 243 come with 1.7 or are u talking about the atock in the 317 s

 

I had a stock LQ9 with 243 heads, stock exhaust manifolds, stock cam, etc.... Here is my dyno graph. The bottom one is with an LS2 intake, the top is a FAST 92mm.

 

From the little that I know, the only LS motor with anything other than 1.7 ratio rockers is the LS7. It has 1.8's. I've been wrong before.....but...

 

That's a pretty damn good advertisement for the FAST intake. No power band you're waiting for. Pretty much nice gains from the get go to the let go

 

I relize my mistake I meant to say I want to upgrade to 1.8 rocker not 1.7 and I was wondering which springs and rods I would need if I use the stock ls2 head gaskets ?

 

with stock 64cc 243s your looking at 10.9.1 on a LQ9 with stock mls .051 gaskets

 

Thanx everyone for ur feed back