Boxerworks.com

Duane... you should write a book. seriously.
i'd gladly spend $30 to have a book of all your tips, tricks and procedures in my garage next to my workbench.
Unfortunately i was born in the era these bikes were made so i only have the past 11 years of DIY knowledge since i have owned BMWs. And the local BMW mechanics in Los Angeles are total flakes (3 weeks to get a tire changed only to have it done wrong).

All the SS pushrod tubes I haveseen have fixed collars.
I would be happyto use a drift on them.
When fitting SS tubes you need to measure the position of the old tubes first so youget the collar at the right position, so that you don't end up putting too much pressure on the seals.

The correct position is so that a straight line extended along the base of the cylinder (where it contacts the engine case) would just touch the most inside portion of the ring. The ring will be angled w.r.t. the cylinder base, but the point that is closest to the engine case would be exactly parallel with the line formed by the cylinder base.

Kurt in S.A.