The FR 32 is a very good cam as a first start to tuning the pinto. I ran one in a standard engine, then over time I added a large inlet valve head, then twin 40s.
The cam ran well in all these configurations. Although the spec does say from 2500 rpm, thats when it starts pulling really well, but It still has plenty of torque from 2000 upwards.
The cam itself wont cause overheating. I'd look at checking cam timing, ignition timing, thermostat installed right way round, no air locks in the cooling system.
To get the best from the cam you need a modified dizzy. The cam needs more advance at tickover, without altering the maximum advance, a standard dizzy will result in a lumpy tickover.