you first need to get your advance curve perfected for your combination. initial timing and total mechanical timing. if the setup you have runs the best at 32*, then you can usually add around 10* or so of vacuum advance at cruise, which will give you better driveability, as well as better gas mileage.
rick eherenburg [member here] did a vacuum advance tuning article in mopar action magazine some time ago, explaining all the benefits of using it. however, it does take a little effort to find out the best combination for your application.
you mentioned a bucking condition when you hooked yours up. have you done anything inside your distributor, such as altering the advance slots or changing the springs, or is it just a stock setup ?
you can hook up the vacuum can to ported vacuum at the carb, or manifold vacuum [full time], and the can has a 3/32 allen screw accessible through the hose nipple that can slow down the diaphragm apply.
i know i have that article somewhere, but you may want to google "vacuum tuning" to see if you can find it.
also, FBO ignition has a plate you can plop in a stock distributor that allows you to set more initial, then the plate limits your mechanical total. that allows you then to tune your vacuum advance to your liking without sacrificing your initial timing.
hope this helps some.