vac. advance canister ?

[geezer#99]

I think you’re right.
The higher performance motors produce less vacuum so the vac pot reacts at a lower vacuum.
It’s always been a bit of voodoo to me too!

[TexasT]

Originally Posted by Dead Parrot

A lot of the adjustable units only adjust how much advance you get, not when it comes in. And some of them come in pretty fast once you hit the magic vacuum. Almost a binary on/off switch.

I don't know of any vac advance that does any more than adjust the timing based on the vacuum or lack of it the engine is producing. The adjustable ones can give more or less with the allen key to adjust it. Also op should look at the max advance on the mechanical weights and possibly make adjustments there.

http://v8buick.com/index.php?threads...uick-v8.63475/
Here is a pretty informative thread about timing and adjusting such. Just replace Buick with Chevy as you are reading.