Do you know anything about these blocks?

[schiker]

I quickly read the ebay ad and it says 1/2 NPT oil cooler ports. I thought GM up'ed the size in the quest for better cooling near the end of production. My 97 has 1/2 NPT but I thought the last years were 5/8 or 3/4 NPT ?????

 

[bison]

I am not trying to be a butt head but there needs to be a distinction here. There is no real unique art to casting engines and the patent for the indirect Diesel engine is long expired. So anyone can reverse engineer and manufacture a 6.5. BUT what is wrong is trademark infringement of AM General's product recognition. GM sold the rights to the tooling (they did the engineering specs for ) and engineering knowledge. Along with some trademark rights to market back to GM customers. Legal stuff too with suppling the govt and GM with engines ( I suppose until Warranty expired on the last production vehicles and until Govt contracts ran out).

So its not illegal or unethical to sell "knock off parts" as long as they don't claim to be AM general / GEP or any affiliation with said mfg. Its a very gray area to say equivalent or same as. They should come out and say who they are and trademark or label the blocks like Motown or others who "copy" other blocks.

Does any other diesel engine get copied as much as the 6.5 ???? Or was it picked due to qty GM mfg and are failing that need replacing but people don't want to spend too much money on GEP engines in older vehicles ???

5.9 cummins,cat and many others are reproduced in china.They even advertize a GM 6.5 inline 4 cyl.