That's good news. let the engine builders experiment within some rules, keep them liberal enough so non mainstream engines can compete.
I think you should keep your first year of doing this simple so it goes smooth with less chance of things going wrong.
Although I would like to see a small block limited cube class..min 355, max 365. No factoring, factory block, non factory stroke/bore ok, any steel rod, any ring pack(3), wet sump, any catalog pan, any headers that fit the dyno(no crossover or upswept) , 11.5 comp? Any cam(no mushroom lifters), .750" max lift, 1.8 max ratio rocker, iron or aluminum 2 valve head(no billet or custom one offs), any port mods within the port casting(welding &epoxy ok), int port entrance must be within 1" of factory port centerline horizontal&vertical, any valve size(no Ti), any cast single 4 intake with a catalog #, any port mods within the casting. Carb, EFI ignition?
1975 and earlier chev, ford Windsor&Cleveland, Pontiac, mopar, AMC, Buick, Olds ...could easily fit this cube range.
3500 to 8k