This distributor is 3/8” narrower and almost 1” shorter than a standard distributor. High output magnetic pick-up provides the most accurate way to trigger your ignition. Plus, with no moving parts to wear or adjust, this distributor is maintenance-free! – SLIP COLLAR BENEFITS – The adjustable slip collar allows you to compensate for machining of the engine block, intake manifold, or heads. The adjustable collar will ensure that you obtain the correct gear mesh as well as the oil pump distributor shaft overlap.