I have been running with no vac. advance for quite a while. Mallory Mag. pickup elec. distributor in a 383 with a 238 / 242 @ .050 cam. No issues, motor runs great. I recently read, however, that vacuum advance can make a huge difference in MPG in part throttle, around town driving. So I decided to give it a try.

Imediately upon hooking it up, the idle raised a bit. I adjusted the idle down with the carb idle screw, and noted that back at the same RPM, it seemed a bit smoother. Took it for a drive. The only real appreciable difference I noted was that now the car now pings horribly when coming up a hill, or when accellerating. (Cant have this). The timing has been set at 24* initial, with 14* mechanical, for 38* total. Obviously, I could back off the initial, and add some mechanical, So with the vacuum, it would be about where it is now. But if thats the case, why bother with the vacuum? What should I do at this point? (my impulse is to remove the vacuum, & go back to where I was, in ignorant bliss of fuel economy)


LemonWedge - Street heavy / Strip ready - 11.07 @ 120