i recently came across a 1965 ford fairlane 500 sport coupe 289. how can i tell if it is a hipo or not besides the 6 bolt bellhousing without taking it apart

 

Exhaust manifolds would be different.

 

Actually 6-bolt bell housing wouldn't matter anyway - '67 or '68 (I forget exactly) U.S. 289's had 6-bolt bellhousings on non-performance engines. I own one (paid $75 at a salvage yard ten years ago - added new gaskets and been driving it since coupled to a 351 Thunderbird transmission).