Aftermarket cylinder heads

[reelmin]

I was told that there are aftermarket cylinder heads availible for the 6.5. They are supposed to be an improved casting over stock. Has anyone heard of this or had any experience with aftermarket heads? If so how about price and where to buy?

Thanks , John

[charliepeterson]

I would stick to one of the venders here. They drive what we drive and know what we want in quality work.

[tom.mcinerney]

John,
The head castings were improved in '97, and then again since. Fortunately, they are still in production, since they continue to be used in the Hummers. Unfortunately, even current heads still have valve seats machined from the cast iron comprising the head. [The seat area is induction hardened, which leaves it susceptible to cracking].
Strongly suggest get new heads, or quality reconditioned heads. Don't bother with used. The recon'd heads need have valve seat inserts installed, and coolant passages 'sleeved', as a minimum. The best thing would probably be new castings, upgraded with valve seat installation.
Can get new heads from Peninsular Engines for less than $600ea. These are current production from Hummer production run. Can get from dealer for $800-1200. Can get reconditioned for $4-500. If late(post '97) castings, this a nice option...Avant Salvage/Diesel Depot and Kennedy Diesel both reliable sources of reconditioned heads.