Distributor Cap?

Hello. I changed my distributor to a single point distributor. Now I am in the process of converting to the pertronix kit for electronic ignition. And what kind of cap should I be using? The one with the black vent on the top or one without a vent? And can you tell me where I can find the right cap I need? Because I'm taking out the dual point Accel distributor. Thanks.

The best caps are the ones with the ribs on the inside and #1 #1 BRASS terminals. I think these are tan in color as opposed to the black ones but I ain't 100% sure on that but I hear tan mentioned quite often as the one to locate tho I am guessing there is no difference in the material composition between the two ex for the color but if you get brass/ribbed you're set. A vent (factory or added) is a good idea as it lets ionized air molecules escape when they reportedly can promote crossfire if thick enough sorta like lightning hitting a tree with wide branches and everything vertical down to the ground underneath the branches (including an unsuspecting person caught in a downour) will be elecrocuted tho the factory vent post is insightly. If you drill a 1/2" hole in the cap top flat 2/3 of the way between the center post & the #1 cap terminal you will be able to check rotor phasing & unplug/plug the vac adv in & see how it shifts the rotor as vac adv is the only system that changes it & if you are on ported be slightly above that (idle speed) so the can is getting vacuum