Hello, I have a question related to manifold vs. ported vacuum for the vacuum advance. I know it's not directly related to this thread. But I have a 67 R/T with a 440 that has a Speed Pro cam that's 300/300 at the seat 230/230@.050, 109 LSA and .480 lift. With the vacuum advance hooked to the ported connection(factory) port on the carb the idle is somewhat choppy. I was advised to connect the vacuum advance to manifold vacuum, which I did and this really cleaned up the idle. I almost forgot to mention that I have a six pack setup on the car as well. Does anyone see a problem with using the manifold vacuum for the vacuum advance with this setup? Thanks everyone!
Not an expert, I think what's happened is you've added a bunch of initial timing through the vacuum advance and disturbed the operational RPM range aspects of the vacuum advance. I'd put it back to ported, to the center carb metering block and go back and add initial timing to see if the idle stays "cleaned up". 2ยข
