The only ones I know for sure are the Super Chevy Show at Summit Raceway in July and NMCA LSX Shootout in October in Memphis, TN.
I just signed up for that board, awaiting activation. 
SixSpeed454SS
I did the long haul last year. Arkansas is a dump.
Can you get some deals from Tramec? I need a spare T56.
Next year I want to drive it in something other than a rental car. If my car is running good and the body gets cleaned up a bit, I’m taking it.
I don’t actually work for Tremec. Events like this are usually contracted out except for one or two guys and they only sell their trannies through about 10 vendors. Transmissions can’t be bought direct.
I still have a ton of photos to sort through. If I find any good ones, I’ll post it up.