Vacuum Advance Timing Question

[Montana71-F100]

Use a ported vacuum point, not manifold vacuum.

According to this, manifold vacuum is the way to go:
http://chevellestuff.net/tech/articles/vacuum

[colnago]

Use a ported vacuum point, not manifold vacuum.

According to this, manifold vacuum is the way to go:
http://chevellestuff.net/tech/articles/vacuum

Uh-oh, the gauntlet has been thrown down. Ported vs manifold (or Ford vs Chevy, since the link is to a Chevelle site). This oughta be better than an oil thread!

Joseph

[Cal2121]

I'm definitely open to input on whether to use ported versus manifold vacuum. My engine builder did not give me a bright line, but said to see what seems to make it run best. Right now, I'm at 10 degrees initial timing and 35 total timing. It seems to run a bit better (idle, throttle response, etc) on the manifold vacuum. I also did some research online and found many threads discussing this topic, and none really focused on the brand of engine. It seemed that most people recommended manifold vacuum. Given that and the fact that the engine seems to like manifold vacuum better, I went with that. But as I said, I'm open to hearing all input.

Thanks again.