Mr. Merk

I thought I had a free set of 243s out of a core engine we were swapping at work.

Turned out I'll have to fork out a max of $150 for the engine. Maybe less for just the heads.

I was quoted $200 just to check & mill the heads .030 before reassembly.

or

$550 to do all of the above plus some cleanup, porting, valve job & bowl work

add about $60 for yellow springs


So max I'm looking at about $750 for how much hp?

or

$400 for basically untouched heads and some springs


I was planning on finding a cheapity cheap ls6 cam. This truck is last on the bottom of our hotrod list, just a daily driver that occasionally will pull the others to the track & back.

14psisupra

iTrader: (1)

I paid and sold mine for 400 about 2 years ago

bobfig

sounds like a plan. you would boost compression a little and have longer runners and a bigger intake port.


243
Heads: 2001+ LS6 5.7 liter passenger car
Material:Aluminum
Part Number: 12564243

Combustion chamber Volume:64.45cc
Compression Ratio:10.5:1
Intake port Volume:210cc
Exhaust Port Volume:75cc
Intake valve Diameter:2.00-inches
Exhaust valve Diameter:1.55-inches

What you need to know:
The LS6 cylinder heads is essentially a tuned-up version of the LS1 head. At 65cc, the combustion chamber is slightly smaller and more efficient than the LS1. The more efficient design shortens burn times and ultimately means less ignition timing advance is required to produce the same power. And because less timing allows more efficient combustion, the Ls6 heads allow the engine to produce more torque. The exhaust port is a unique D-shape that improves flow. LS6 heads are the best choice only when all-out power is needed. Be prepared for a big price tag at the dealer or steep core charge from your head porter.

Ferocity02

iTrader: (59)

I bought my assembled 799's (same at 243) new for $460 shipped. I sent them to WCCH to be milled for $70.

Vortec350ss

iTrader: (20)

Are they going on the 5.3? If so they will need to be milled to keep compression where it is I believe...

TXsilverado

iTrader: (19)

save money and leave it stock IMO. maybe invest in a good custom tune.

what is the casting # on your heads? i thought the 05 came with 799 and 243 heads?

Mr. Merk

no, stock is 706 or 862 ****

these are 243s.....i'm thinking about just tossing them on stock without porting


I don't think I can justify the extra $350 unless it will give me THAT MUCH more power. Especially after buying that firearm yesterday

1FastBrick

iTrader: (17)

in 05, Only the L33 came with the 799/243 heads. When they switched the body style on the Tahoes and suburbans is when the heads started to show up on other 5.3L engines.