Highflight

That is absolutely correct, and it did create a bit of a difficulty. I remember in the later 80's when a C3 body panel would come to my shop from my GM supplier as a replacement part, and it was CLEARLY the "new" SMC material.
I honestly forget what we used to bond these panels back then because I'm just too damn old and tired to remember. What I do recall is that we used an official "GM Approved/Mandated" product that we would buy from the Chevy dealers at the time. It was fun trying to get insurance companies to pay for the high-dollar stuff.
But that was just for bonding and filling the bonded seam.
Crack repair of these panels was a mystery on the part of GM people at the time, so I/we had to rely on moving over to epoxy resin and mat which did work as a repair material.

The incompatible SMC panels are really easy to identity when you grind them open, so I am going to have to stay with my recommendation to use polyester resin to repair any pre-84 Corvette UNLESS it is shown to have had an "84+" panel installed in a previous repair.

And about derekd8915... he seems to really have the hots for you. Y'all should get a room.
I think he doesn't understand that there really is more than just one exact way to do things because individual situations sometimes require it. I've read more MSDS and instructional sheets during my time with my collision shop than I care to admit, and I sometimes wondered whether an attorney or a monkey (same thing) wrote some of them.

DUB

Thanks for your input and I agree as you can see in this thread that following the written word on a sheet of technical instructions DOES NOT mean jack squat and often times...like I previously wrote....it is the standard that was approved so people can use the product and keep it in the range of how it was designed and be able to be warrantied IF the instructions are followed to the letter and there is a problem.....but DOES NOT mean that the 'standard' can be altered and still provide a quality repair.

And...for the record... though he may be a great guy to those how care about him....there is no way in hell I would get room with him.

​​​​​​​DUB