It's not necessarily that you guys have to switch to other motors, but that when you go to other tracks you'll have a legal car to run in mod, and out of towners can race SC at your track. Me for example, I run an 8.5 in my SC at home, I don't even own a 17.5 and definitely wouldn't buy one just to race for a night or two here and there.

Mod is the way SC is growing, we now have two classes at rce, mod: which is open motor to any 2wd SC, then spec: no timing on the speedo, 17.5, any tires/bodies.