Question on installing ski rack on on 36" wall space
Assuming not much is as stake, the idea is reasonable if the rack will still 'work' when it is 1.5" from the wall.  I suggest screws or lags of whatever type you have on hand, long enough to drive 1.5" into the stud, placed 3/4" from the top of the 2x4 cleat, one per stud, assuming you can tighten the screws enough to fasten the cleat tightly to the wall. Then mount the ski rack to the middle or lower half of the cleat.  Be careful of electrical and plumbing in the wall. However, all that's a lot of extra work that will end up looking cludgy.  I'd be more inclined to drill new holes in the rack that align with the studs.