Will OEM GM LS6 / LS2 cylinder heads, casting #243 with the D-shaped exhaust port fit my 99 LS1. I believe these heads are coming off a 05-06 Trailblazer!

 

Yes, you'll need gaskets and bolts.

 

yep sure will

 

Awesome, what are your guys opinions good upgrade or what? I Haven't decided yet on what I want to for a cam, but im thinking PSI valve springs and titanium retainers that would accommodate up to a .625 lift. I was talking to someone and they weren't sure on if those heads would work or not beings the lS2 has a larger bore, so thats why I posted I figured yall would know.

Also, Oil pump my car has 28k on it, how hard is it do the oil pump, im doing all this work from top side, ill also be putting in a set of LS7 Lifters (the reason im tearing down is I think I have a screwed up lifter on cylinder 4 or something in the valve train let loose). Any other supporting mods or good mods to do while im in the there Cam Chain etc.....

 

243 heads are used on newer 5.3 truck engines and 4.8 too I think

 

You will have to lower the oil pan to access the bolt for the pickup tube to pump.

 

Ya I have a buddy telling me to go with 5.3L heads for my car, and so your telling me these are the same heads as the newer 5.3s??

 

Whats a good deal for these heads with nothing on them??

 

not sure on price, but yes these are the 5.3 heads used on newer trucks. Same casting as LS6 heads but without the sodium filled valves.