The first A1-Cardone replacement distributor came in the mail 2 days ago. tested the vacuum advance, their was a leak, couldnt hold any vacuum. So I called Summit Racing and they shipped one out that arrived today. I dont know why I didnt test it first, I was probably just in a rush to get the car back on the road. I re-curved the distributer with the stock light spring and 1 mr gasket spring. Got everything hooked back up and new brass distributor cap.... finally thought to test the vacuum advance and.. it leaks. 2 in a row. Never buying that brand again. Im going to try to switch the working vacuum advance from my old distributor to this one.