There have been several postings in the past from people who have modified their SU air cleaners using different replaceable air filter elements. So this is not a new idea - just another filter element source. I came across a replacement for Kohler Air Filter #4508302 at Lowes: 6" diameter, 3" thick. The nice thing about this filter is that it comes with a washable, foam pre-filter sleeve, which is originally gray, but which I painted red, for eye-appeal, with some Plasti-Kote Vinyl Color I still had on hand. The pre-filter gets a few drops of oil to help it filter out more dust. The procedure is to liberate the two cover plates of the SU air cleaners and to sandwich the filter element beween them, after trimming the rubber end-seals a little bit and making up some 3" long spacer tubes that the bolts go through to hold the gadgets to the carbs. I did this with two-hole filters, but the effort is really more worthwhile if you need to replace your three-holers, which are harder to come by and more expensive.

Bob S.