On that metric/non-metric bolt thing...
Here's the deal. GM started a major overhaul of their designs in 1976, inspired by the oil embargo in 1973/74. They announced that they were going over to metric fasteners, but only on newly redesigned parts. So, if you had a part that was the same as previous years, it had ASE bolts. If it was a new part, it had metric bolts. This made it necessary to keep two whole sets of tools so that you could work on your car.
I had a 1982 Pontiac Phoenix. ALL the parts on it were metric, except the engine parts, since it had the old Iron Duke engine.