63-your truck has a vacuum advance distributor, right? Just find out where it taps into the manifold and get a double fitting to go there. My '72 Malibu (with 307 V-8 and points) had a fitting at the back of the intake, which had a large opening for the brake booster and a smaller opening for the vacuum advance line. Try scrounging at your local boneyard-a V-8 powered vehicle should have what you need, or you could also look at newer I-6 powered trucks/cars too. Hope this helps.

Regards,
Wannabe smile

"Don't expect anything and you'll never be disappointed"