I am getting ready to buy one of the MSD billet distributors and was wondering if I should get it with vacumn advance or not. The engine is going into a heavy street rod . It has a mild cam and will have headers on it and I want to run dual quads eventually. What are advantage / disadvantages to having / not having the vacumn advance ?
I know I took a gas mileage hit when I put the all mechanical MSD distributor in. Otherwise it works excellent.
If it is a street car, and you are at all concerned with gas mileage, you want vacuum advance. Before you go and buy an MSD distributor, consider this option: www.davessmallbodyheis.com I have one of Daves distributors in my car, and I run an MSD Digital 6+ box. Dave will rebuild a points distributor, soup to nuts, custom curve it, install an MSD magnetic pickup, and give you a tailored vacuum advance, with a premium distributor cap for under 150.00. And it will plug right into any MSD box. To me, it was a no brainer.
For any vehicle that runs at part throttle, vacuum advance will generally provide better throttle response, better fuel economy, better part throttle power, and cooler engine temperature. You need vacuum advance.
