How much differencewould a vaccum advance dristributor make vs. a non-vaccum advance distributor? Like any horsepower gains or anything like that?

 

A vacum distributor will get better mpg while driving normal....normal being not how speed freaks drive. It will also allow for use of a lower octane fuel. If absolute go fast is your goal a mechanical unit has the advantage. But if money is no object....MSD makes some really trick stuff. Best of both worlds sort of thing.

 

There are a few aftermarket distributors that also offer an electronic advance...which is also the case for the MSD ignition system with the right modules.

 

MSD does sell an all-in-one unit that has the advance curve built right in the unit so no extra boxes..

 

I run straight mechanical, drive it every day with decent mileage and no problems. If you wanna go performance and are trying to save a few bucks, srtaight mechnical isn't a bad route