More Iso. questions

This thread may be very similar to Shillings but I don't want to be accused of hijacking.

I went for a long ride the other day and realized there was enough vibration coming thru the bars to cause my throttle hand to go numb over time. I guess my previous rides were too short to notice how bad the vibes were. I increased the front iso. clearance by an additional .005 to get that lovely smoothness above 3K that everyone has mentioned. All good. The buzz at the footpegs is another matter.
I recently installed the AN vernier iso. at the rear due to the lack of access so making changes is quite easy. The vibration at the pegs is tolerable because I can move my feet around more than my hands but no amount of adjusting seems to help. I also have DIY rearsets so my footpegs bolt to the Z plates where the passenger pegs normally attach.
Could it be that the original extended footrest assembly and rubber work to help dampen vibration. If those of you with perfectly tuned rear isos move your feet to the passenger foot rests due you feel more vibration? As I say, my vibration is tolerable but I get freaked out by stories of cracked frames due to poorly adjusted rear isolastics.

I've been told by a lifelong Norton shop owner that the MK III adjustable iso's are made stiffer than the rubber in the MK II non adjusting type b/c of the overall heavier engine assembly weight with eStart paraphernalia. He said using the III setup on a II will never get you the renowned Norton smoothness.

Some on this forum have stated the aftermarket rubbers are harder than OE and this is why some find ride too vibie after iso renewals.
I think I read the Hobot took a Dremel to his rubbers to shave down to 1/4"?? Taper around periphery.

Thanks Tornado, that may be the case.
I recall Hobot modifying the rubbers.

I didn't take any photos when I installed the rear AN vernier kit but it was a PITA. The threaded inner tube is much longer than the original so it makes the cradle quite a bit wider. I had removed the GB, and swing arm to get the cradle out the rear to make it easier to remove and re-install the rubbers. In order to get it back into the frame the front and top engine mounts had to be removed to shift the engine forwards and up. If I had to do it again I would try to re and re the rubbers with the cradle still within the frame.

For your foot peg vibe question, can you reinstall the original pegs to get a few test runs in? Who knows what the harmonics are like with your homemade rearsets...