Heavy Duty air cleaner was an oiled foam prefilter that wrapped around the paper element.

I'm not certain about '68, but the '69 YT 400 did come with the chrome air cleaner lid and rocker covers.

1111270 appears to be correct for '68 400 with auto trans. All those I've seen have been the dual port vacuum advance; vacuum advance on the front of the canister, vacuum retard on the rear of the canister.