Quote:

My guess is the 76 model engine was built in 75.



the casting number won't dictate what model year and engine was built for.

As far as the conflicting info , I don't see any , the factory would start producing the a new casting ahead of the actual need . take the 400 engine , not available till 1972 but the castings started being done long before the actual model year.

I think the -4 would be the number of repairs to the core box , I get confused on that one.