i did exactly that with my mac adjustable and a fixed msd,at 34 with the msd my mac showed 33.i also have 2 snap on adj lites but never tested them.i like the mac better,it is really bright and i can use it in a boat in the sun.

I have a old craftsman TL to but have about 5 others ( different brands) . FWIW a lot of techs in the marine industry use different model Ferret timing lights. Just saying

When I get some nitrous motors in my Boat I`ll be sure to go back to a $20 light thanx for the tip BB.
Yeah my motors have blow by, I didn`t build em and I`m unwilling to rebuild em for just that reason.
One day .... till then puke tanks. CHOO CHOOOO!!

I have yet to see one picture, video, dyno, test, results etc from you.. lots of internet 'facts' thou.
Cheers

Never seen a bunch of guys get there panties in a bunch over a timing light before. This is hilarious. Carry on.

^^^^ the good, the bad, the ugly and perfect timing for that post - no pun intended. - just messin