I have the same setup. RS front end, stock plugs, head conversion. With the stock bodywork, I had to trim the plastic a little, but the plug still does not protrude past the plastic. And I never have a problem with the tire getting anywhere near hitting the plastic.
VHM heads would be a different story, though. Those heads have the plugs dead center and sticking straight out the top, not angled like the NSR top head. You may have some clearance issues there.
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Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
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