I'll see what I can do. In the late eighties....I think 87, not sure, I attended the last manufacturer's show at Speed distributors in Atlanta. Speed Distributors was a wholesale only automotive outlet similar to Summit, but much smaller, that sold to retail speed shops across the southeast. They are now defunkt. they used to host a really cool show anually, where they would have all the big wigs from all the major brands there. Anyway, the last time I was there, I actually got to talk to Doug Thorley hisself! We had a nice chat and that included his thoughts on exhaust reversion. In a nutshell, I remember him saying that all reversion is, is the exhaust trying to move backwards in the header tubes on overlap (when both valves are open) at low engine speeds. He was a very to the point and astute gentleman.....even genius, perhaps. I really used to enjoy those shows a lot. Got to meet several legends. Dick Landy, Doug Thorley, Don Garlits, Don Prudhome, Vic Edelbrock, Smokey Yunick...and even more. We were just a small machine shop in Macon, but we ordered enough speed equipment from them each year to always get invitations, so we always went. I miss those days.