My 04 gmc X-cab stepside has 862 casting heads. I haven't seen anybody mention these heads here, are they the common heads on the 5.3 or what? anybody know? also someone said that patriot sells 243 heads for $400 or so but I don't see them on the website.

 

Pretty much the 862 and 706's are the standard 5.3l heads up to '07. The 243 heads have slightly larger combustion chambers (65cc) while the 862 heads have 61cc chambers. The intake valves are also larger on the 243's and they have better flowing ports. Not a bad swap if you get the 243's milled .020" to bring the chambers back down to the stock 61cc chambers.

Richard

 

Not to thread jack but i was curious about the 243's used on the 07+ 5.3's. Are they identical to the Ls6 heads minus the sodium filled valves?

 

https://www.performancetrucks.net/fo...ghlight=%23853

 

thank ya