On my SRX I put a 192 3/8" longer than the track, as close to the slides, inside & outside of the slides, V-ing out every three bars. With 8" of carbides on the ski. On the trailes it doesn't slide corners but it turns, stops, & accelerates on a dime & will make change. Add a 1/4" plate to the heat exchange protectors.
Nobody, NOBODY, ever beat me out of the hole with my clucth & gear package on ice. I digges 4 1" wide ruts for 12' & then it's hooked, & gone. People who road it said they couldn't beleive you could make a sled handle & stick to the ground like it did.