Your best bet is to find a 228 complete with the oil pan, front timing plate and oil pump. You might also see if you can get a working vacuum advance and distributor from the smaller 228. Would be good to get the small bell housing as well . . . the bell housing on a COE motor is a boat anchor.
While you have it apart, consider a full flow oil conversion as well.
All 302's have a six bolt flywheel. The flywheel on the COE motor is likely a large diameter recessed unit . . . another boat anchor. You will want a flywheel off a 248 or 270 with the 6 bolt pattern. As mentioned, you can make either a 12V or 6V ring gear and starter work on 12V. You will be happier with a 12V system when it comes to options for an ignition system.
The Nicson cast exhaust manifolds are a great fit and the Nicson dual carb intakes work well too.
Even with the small 228 oil pan (8 quarts) you may still need to section and weld it to get it to clear your front suspension. You will likely have a little creative work to get the rear motor mounts to work as well.
If you got the updraft intake / exhaust combo, keep this for trade bait as it is worth comparably more than a standard intake to the right guys.
Sounds like a fun project.
