I have a 1940 GMC one ton with a 1955 248 engine. I want to fine tune the timing. First time timing a vehicle. I have read past posts stating using the bb or U|C with the "|" as the mark for TDC. The truck sounds good running but just want to make sure everything is up to snuff. I unhooked and plugged the vaccum line. Started the truck and set it at TDC per the "l" between the U and C. If I use the bb it idles too fast. The octane selector is set about 2 or 3 degrees of advance at this stage. I have my idle adjustment screw 1 and 1/2 turns out. I adjusted the distributor with a timing light so I would be right on the "|" between the U and C. Sound good? Do I need to check the vacuum timing or am I good?
Thanks in advance,
Bill