4spd swap checklist for a 68 Dart GT 318/904

FlamesAreWicked said
After scouring the internet in dozens upon dozens of forum threads.. some have said they’ve never seen a small block that wasn’t, others have said that all pre-70 small blocks were drilled.. and some have said it’s a mixed bag..

The alignment tool I have is from brewers, it’s essentially an input shaft cut down to be used as an alignment tool so.. if that fits, I should be covered..

That's one way to do it I guess, but I don't know how you would know you are shoving it in the hole far enough. Too far doesn't really matter. I found the diagram: