Huh, that seems weird to me. There were a ton of 390's made throughout the years - mine is out of a 67 LTD. You would think the big parts warehouses would have the correct one.
Found this, a bit long read but tons of info. I had thought the rib should hit the block to set the depth but this says no. Go down to the part, "Installing removing dipstick tube".
Anyway, I gotta go now, but I'll see what i can find on a 1967 LTD 390 as far as oil capacity.
thx again, Dave