That was the real beginning of the end for gm-all of their divisions had their own engineers-their own engines-and their own exclusive innovations. That breeded competition within the company-and that was what made them king. They (the company) then decided if they basically just made 'em all Chevys, it would save a ton of money. 1/5 of the designers, engineers, etc;needed. They eliminated all those white-collar types back then. Let's not lay this solely at the feet of unions, because gm's been only interested in profit, and not quality or their customers, for many years-which is why they've gotten their ass kicked by the Japanese and Germans, once those countries got their act together on automobile manufacturing.
That's true, but much of that cost cutting was brought on to GM because of ever increasing wage and benifit costs demanded by the unions. GN had to make up for expensive union settlements somehow. Cutting back on casting plants for things like the old rocket engines was one of them.