[Joe B.]

Good point. I have 3 Made in china from a popular 49-51 mail order place and they all leak down regardless of the vacuum applied. Finally got smart and ordered one from a local napa. Echlin made in Mexico. The website said it would not fit my '50, but it looked identical. Put the vacuum pump on it at the store counter, low and behold, it held rock steady at 6 lbs. There is a slight difference. I needed to drill a tiny hole in the arm in a different location for the retaining clip. It's in and all is good. For any 49-51 guys out there, I suggest getting the Napa ECH VC915. PS, I also checked the vacuum at the carb fitting and it varies from 2-6# as it should depending on rpm's.