4100 timing question

Well the regular timing setting is 10 Degrees BTDC, you can run it at 13 degrees but you would have to use premium.I always wanted to do it on my '87 4.1 but I never got around to it. Now I wanna do it to my 4.9 , that thing is one mean beast. I wouldnt put a whole lotta money into an HT4100, its really isnt worth it IMO.

You should probably run premium for any timing advance, I would atleast run mid-grade. A knock sensor would be nice...