The engine has no clue who built it. Claiming XX total timing is THE number is just wrong. Timing lights don’t all read the same. 3-4 degrees difference is common. That also means that initial timing can vary that far. The only way to get the initial correct is to test for it. Once that is correct you can work in total timing and thats done by reading the plugs. Once you get the total correct you can work on the curve. Or better yet, start out with a guy who has tuned distributors for awhile like Halifaxhops and let him dial in your distributor on his machine.
