'71 198 swap to a '76 225 - help identifying noise?

Found it! Pulled the dipstick and the noise went away. No amount of bending the dipstick or putting it in a different orientation changed it, so just left it out. Dumb thing!

Anyways, the thin flimsy bellhousing cover is off since that was rubbing too. Can I leave it off? Is it really that critical?