The correct pan will have an 893 stamped into the bottom of the pan. That was the same pan used on all BB a bodies 67-69 except hemi. I warn you thought the pan is quite pricey at least $300-400 for a nice unmolested one.
I'm driving a BB car and trying to make sure I have all of the correct pieces for a someday restoration. The good news is the list of things I need is getting shorter- the bad news is I haven't seen one or two things ever.