I've spent a lot of time with my 74 Monaco's radiator so I figured I'd post some stuff in case it was useful to anyone else. I have a 74 Monaco coupe 360. When I got it the radiator core was shot and both tanks were damaged to the point of having cracks. It is labeled 3692946 59538 on the top tank. It didn't seem to have been replaced at any point and the first number comes up here as being original for a 74 C-body with a small block. http://www.rosevillemoparts.com/reference_radiatorguide.php It has a 2.5in tank width. Transmission cooling ports are 12in apart. CCEGR port is on the passenger side. There are four 'bumps' on the rear of the core frame, one for each radiator shroud bolt. The radiator overflow nozzle is at an angle compared to the axis of the tank. I picked up a radiator core from Murray Park for this car. It is labeled 016946 59538. I cannot find reference to the 016946 anywhere but the 59538 matches the car's original. It has a 2in tank width Transmission cooling ports are 15in apart. CCEGR port is on the driver's side. There are six bumps on the rear of the core frame, one for each radiator shroud bolt and one that used to hold a metal rod, now gone after re-coring. The radiator overflow nozzle is parallel to the axis of the tank. The mounting brackets are identical for both. I hope this helps someone dealing with a "formal" smallblock radiator.