Ditto on the additional clearance when cold. I added .004" for cold setting on my highly worn valve train and it was spot on when I rechecked when warmed up.
re, coolant leak. That much leak to the sump would seem to make it a direct leak and not going through the cylinders.
I have a 216 and have no experience w/a 235 so my following suggestion should be taken w/the proverbial grain of salt. (disclaimer)
My 216's valve train gets its oil from a copper tube that feeds through the waterjacket of the block. I think 235's have this same feed but am unsure. If so, did you happen to loosen either fitting on this pipe? They'll leak afterwards.
Otherwise it looks like you're going to have to pull the head and look for mismatched head to block holes, pinched head gasket or cracks.
Good luck
Dave
