The reality of the GM enigine is that this is one of the only cast iron 6 cylinder engines that is used in industrial applications. As far as I know Toyota does not build a cast iron V6 or V8.
The volume is simply not there to justify designing and building a new engine.
Also Toyota and GM have a relationship on the car side of the business. Toyota builds a few cars for GM and also leases an assembly plant in Ca from GM.
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.