Was it designed souly by Isuzu or was in designed by a team of GM and Isuzu engineers? Anyone have a GM website link that says this or another official site that says who it is really designed by?

 

It was a joint venture by GM and Isuzu (who has a long history in diesel technology), as well as IHI, Garrett, Bosch, AC Delco, Mahle, etc, etc. No "one company" designed it, nor did 2 companies design it.

The engines are assembled in the US from parts from many countries. Japanese content is just a small piece of the puzzle.

 

ok someone on another forum was trying to tell me but I insisted he was wrong, but he tried to tell me and other people the the Duramax was an Isuzu engine and the joint venture ment that GM made the transmission and Isuzu made the engine which doesnt make much since

 

The Allison subsidiary of General Motors adapted the transmissions for use in the pickups. The Allison 1000 series transmission goes in hundreds of different vehicles. Allison, not GM, designs/makes the transmission. This is significant because you can get parts for your Allison from any Allison dealer, not just a Chevy dealer, and you will find the prices are alot better when ordered from Allison.