Does 243s come stock on 5.3s? I have heard people saying that if you put a set of the 243s on a 5.3 you have to mill them to be closer to stock CR. If the heads came stock on that engine, were they milled at the factory or would I see a substantial gain by yanking them and milling them? Any answers or info.....

 

THEY CAME STOCK ON 07 NNBS AND UP 5.3S. on 07 classic and before 5.3s, you would have to mill them to be closer to stock CR. NO NEED TO MILL THEM. HOWEVER DOING SO WOULD BOOST CR BUT FOR THE EXPENSE OF REMOVING INTAKE TO REMOVE HEADS, THEN WAIT ON MILL, ETC, YOU COULD DO BETTER WITH THAT MONEY.

 

Like a ported set of heads that are milled for the CR you want.
PRC Stage 2.5 LS6 CNC Ported Heads

Just a suggestion...

 

@ Jake, I will definately be in the market in a few months. I'm just tired of dumping dollars on it, LOL. If my truck had *****, my wife would have divorced me ALONG time ago.

 

I feel your pain there! For some reason the women (most of them, in my life anyway) don't understand the obsession, but I'm sure there are exceptions out there.

On a more serious note, if you have any other questions, whether it be about the cylinder heads or anything else, please feel free to give us a call!