"...does anyone use a gasket between the nozzle and venturi on the 40 and up carbs,and what if any effect is noticable raising or lowering the nozzle."
Damn good question.
I use a thin seal with any used venturi, just because there is always some wear.
Kyle's question applies to the differences in height of the shoulder beneath the spigot, which was greatly shortened with the M75 and later nozzles. (Sorry, but my comparative pic is on a thumbdrive at the shop, and I can only access this forum on my wife's confuser, as the forum format is WAY too modern. My other PC's just show a black marble background.)
Although I cut .090" PEEK spacers to make the later nozzle's match the original M5's etc., I haven't the slightest clue as to the TRUE effect of raising or lowering the nozzle and its holes. The effect of the holes themselves is pure conjecture, from my studies, anyway!
A savvy dyno operator, which is far, far, far, more rare than dynos, might be able to give us some valuable insights if he had a relatively stock machine to study.
"Second, the ID of the nozzle is considerably smaller for the Indian Linkerts. Any ideas why this is, and what would be the consequence of using an Indian nozzle in carb for a knuck?"
The Bonne Indian nozzle is in the same realm as H-D's, but Indian's Standard nozzle is restricted.
To make things more complicated, the tiny Indian M741's nozzle is virtually the same as H-D's Flatty nozzle even for the ULH.
We can conjure all kinds of un-proveable theories ( I occasionally lay awake at night fretting over nozzle holes, honestly), but I prefer to remain just a student who just reports his findings, for now.
I profess blind faith in the Founders who concocted these miraculous devices in the first place. I prefer at this time to preserve History as it was, although we all hunger to re-write or improveit.
"I recently made a quick and dirty tool..."
Drop the hammer now, and nobody will get hurt!
Think "cam action".
My tool inserts without damage, and a revolution centers the venturi without stress.
I would post a pic, but it's proprietary. (You can fondle it at D-port if you like, but no caliper please!)
Your description of Panic's hole in the disc is a new one to me; I have no experience from the four-wheel'd world at all.
My Victory pamphlet is ancient, and does not mention anything like that.