The outside ac box was missing from my 69 .I traded for one from a 73 or 74 nova w/6cly ,It fit but was broken .I just bought one from a 72 nova (unknown engine) and it does not fit it hits valve cover because lacks a recessed area the other one has. The box halves won't interchange because of slight angle differences. Did anyone else have this problem ? What nova ( other than ventura) has the correct recess for clearance of a pontiac engine ? I thought 68 to 74 was same unless big block chevy.