Yeah , those old stockers came qith around an 8.1 to 1 compression so a sporty with 13.1 would be a bit dangerous to say the least. Didn't notice the re tard thing till I read your post. Political correctness has truly gotten out of hand. Think I'll go edit that post. If talking about the mechanics of timing on an engine using proper terms that have been in use for over 100 years gets anyone that riled , they really need to take a mechanics course.
Is your shovelhead a conehead motor? If it is they have an automatic spark advance built in upon start up of the engine.
Yes. Cone motor. Well familiar with her internals. Done a lot on my own but she could use a rebuild and I don't have a scooter trash network here like I did before we moved. The one nearby shop that doesn't give you a confused look when you say Shovelhead doesn't want to take on a full rebuild. Kinda moot though, since I need to save up some dough anyway.