Having bought a re-manufactured 30-3817 distributor from AutoZone over a year ago with decent improvement in my ignition, I noticed the "flat" acceleration had not been alleviated but in light of the unarguable overall improvement in performance, I considered my $38 well spent, and still do. Still, when I found that the vacuum advance apparently was never anything BUT DECORATIVE on that particular unit, I resolved to remedy the matter as soon as I could afford to. Last week, I bought a brand new 84-3817 Cardone "Select" from CarId for $78, which, considering the outrageous price of vacuum advances for my 66 383 2V, is a BARGAIN of the First Order! I popped it in this evening, fired Mathilda up with an immediate, obvious improvement again, in part due to the fact that replacing points had come due again, as I normally do twice annually, but also with the added bonus of a WORKING vacuum advance! I took Mathilda out on the highway with the utmost satisfaction. Unlike the reman dizzie, which was "Hecho in Mexico con puntas de merde" this set, made in China, surprisingly is very solidly made all through with good heavy duty points and overall top quality workmanship. THAT pleasant surprise seems born out in the initial performance tonight, though I will follow up this post in about a week if anything adverse occurs. Otherwise, consider these a "Good Deal" and a viable alternative to more expensive electronic units. I for one am HUGELY pleased I can continue to run a traditional breaker point ignition with some assurance of newly manufactured replacement parts that will work. I guess Cardone IS exercising good quality control with the sino-slave plant they hired to turn out this product.