timing marks

[yttims]

hello all newbie here got a built cj just got it started yippee..
any way i wanted to set the timing my book says like 5b or 10b . my motor is a 304 with edelbrok performer intake holly 470 truck avenger headers and a ebay hei dist . my biggest problem is the marks on my motor read TDC 5 A10 15 20 THANKS ANY HELP OR CALL ME AT 1 207 457 0371 SMITTY

there is a hole above tdc mark ?? thnks

[tufcj]

Welcome to Bulltear.

All a matter of terminology. Books use "before" TDC, so you get the b5 or b10. On the timing cover they use "advanced" (meaning before), so the marks are 5-10-15-20 degrees advanced (or before) TDC.

The hole is for a probe that some older diagnostic machines used to set timing.

Try yours set to A10 (vacuum advance disconnected and plugged), see if it pings under load. If it does, move it toward 5 about 2 degrees at a time until it doesn't.

Bob
tufcj