I would do a search, but as everyone knows there having problems with it. I googled it, but couldn't find an answer. Basically, I found a carb with a proform main body, which does not have a vacuum source for spark advance. I don't wanna drill the intake. So what are the disadvantages of using my vacuum dizzy as a mechanical distributor on a car that is street driven? I'm guessing I'm gonna have to mess with the springs, which is fine with me because I've done it before.

 

If you know how to set it up you'll be fine. Plan on losing some mileage though. I've had to use a starter retard box on a couple customers cars recently. The motors liked a lot of total advance, but then the base was too much and the starter kicked.

 

The Proform mainbody doesn't have provision for ported vacuum, but you can still use the manifold vacuum port on the throttle body.

 

If you don't have a vacuum advance, you'll need to put in more initial timing, which may (as mentioned above) require a retard box to get it started.

Your gas milage will go way down driving on the street at part throttle cruising. WOT performance will be the same. I ran a straight mechanical distributor for awhile....and I switched back to a vacuum advance. Gas prices are too high nowadays!