Hi Joe,
The Speedi-sleeve is not the solution to timing cover seal leaks. It's USING THE PROPER INSTALLATION PROCESS. Centering the loose timing cover/seal on the HB snout before you draw it (HB) down and tightening the timing cover bolts, insures that you'll have equal pressure around all the seal surface. Smooth seal surface+centered seal=no leaks.
As for adding a Speedi-sleeve; rarely will you find a 50 year old balancer that doesn't have some tracks worn in the seal surface area. A fresh seal on a worn balancer snout is just prolonging a leak. The sleeve gives you a perfectly smooth surface. A new sleeve with an HB drawn down on a bolted down timing cover may or may not center the seal on the HB. Taking a little extra time to install the HB/timing cover correctly will eliminate the need for an illusive "OFFSET SEAL" and save you from how to figure out exactly where to locate the illusive "OFFSET" seal in the timing cover.
Dave
