To add to RR's rod types, I have tapered alloy (duralium) rods in the cafe. About 1/8" thicker in the middle.
Re Trevs clearances. I have to set them at 10 & 12 on the cafe, if I use 8 & 10 she props the valves open when HOT (35degrees 75mph in 3rd up hill).
The recommended settings are just that, recommended. If there are other things/mods at play it's suck n see.
Cheers