Vacuum advance 83 454

[ZacharyDouglas1992]

I need to know whether or not my vacuum advance goes to ported or manifold vacuum on my 454. I have all factory emissions hooked up (ca smog). i'll attach the diagram for my truck. It shows it going from the back of the carb, through a check valve (which is also connected to spark tvs).

thanks for any help. loosely related...

I've got the truck running ok, but its wanting more advance. I currently have it at 6 BTDC. The factory spec is 4 BTDC, 6 should be within the acceptable margin for smog. Motor specs are relatively stock, so is there adjustments to the carb I need to make to help? at 12-16 BTDC it runs pretty fantastic. But, at least for the smog, I can't have it that advanced.

thanks for any advice

Zack