[classicauto]

These guys have you covered.

But a tip for glueing them to add to Ludwigs........

I like to take my vernier's and measure the housing, then bump them out one or two thou from that width. Lock them in place there, and use them as a jig to glue the seals together. You can basically dab some crazy glue on, and jam them in....in about 5-10 seconds you remove them and they'll be exactly spaced so the come apart when the engine's torqued.