anyone know what the difference is? I heard somewhere that the FFV have 36lbs injectors stock, is this true?

 

If all 706 heads were like mine, they have triangles cast into them under the exhaust ports, where as my new ported 862s do not. I read in Car Craft or CHP a while back that the heads with the triangles are cast using a different method and stock are good for around 5 rwhp more than a stock 862 head.

 

thanks tdrumm, now with the other question about them having 36lbs injectors.

 

welp found out about the 706 head casting last night.

4.8L/5.3L Trucks
Both of these engines share a common aluminum head with 71cc chambers.. The 12559862 casting was used from '99-'04, but the 12561706 showed up on some engines in '04, too. The 862 casting came with and without the recess on the edge of the deck surface, so rebuilders need to make sure they use the right head gasket when installing one of these heads

here is the link to the stuff.

http://www.automotiverebuilder.com/ar/eb040538.htm

 

706 and 862 head combustion chambers are 61cc, don't know if that is a typo in that link for not. Also, my early '03 truck came with 706 heads

 

yeah my neighbors 03 truck has the same heads lol, so i guess they just changed casting #'s in 03 and up.