I was just told by a customer service guy at radiator.com that the 2 row radiator will not fit my '91 F150 4X4 manual transmission vehicle which came equipt with the single row radiator. I need more cooling under extreme conditions (climbing with a full load from sea level over an 8000 ft grade off road in 4WD - roughly 5 to 10 miles per hour). This is steep terrain and over the roughly two hour long climb the engine tends to heat up. I does not make any sence to me but if anyone out there knows for sure I would appreciate the info. Thnaks!

 

You could put in a e-fan instead of a bigger radiator - that will help a lot at low speeds.