Hei distributor canister

[tino0217]

I have a 350 small block between 74 and 78 is the year and the vacuum canister makes the distributor cap lean it doesn't sit flush. Without pointing out the obvious do I have the wrong distributor cap is there some type of distributor cap that has a gap or something that allows the distributor cap to sit flush an even without any interference from thevacuum canister? I compared it to the old one that I took off and they look identical I see no difference. but older distributor cap was black and I never noticed if it was not sitting flush or not this new distributor cap is brown and I do notice that it does not sit flush