67 273 Timing

yarcraft91 said
I checked my '67 factory manual for 273 timing specs.

For non C.A.P. engines
Timing spec for a 2bbl manual transmission is 5 degrees BTDC
Timing spec for a 2 bbl automatic and all 4 bbl is 10 degrees BTDC.

All C.A.P. 273's are speced at 5 ATDC.

There are differences in the mechanical advance curves corresponding to the differences in base timing. My electronic aftermarket distributor (installed 1992) appears to have the 2bbl manual mechanical advance curve by default, but both mechanical and vacuum advance are adjustable.

So at 6 BTDC, I'm running close to factory spec for a manual, and so are you at 12 BTDC with an automatic

Yep thats the 67. 64 through 66 FSM may not be the same.
I think the adjustment in the vacuum advance is event like when it comes in or how fast it moves. Doesn't effect the total travel.
Long as it stays disconnected I dont have to worry about it.