Would my '37 1/2 ton clutch be coil spring type or a diaphragm spring type?Also why are there two types? Can either one be installed, if so which is better? Thank you for your help!

If your 1937 had an original 1937 type clutch it would be of the coil spring type. The diaphragm pressure plate was new for 1938. One advantage of the diapphragm type is the pedal depresses easier as it is depressed. You will also have the graphite type throw out bearing where as the 1938 and up had a ball type bearing.
I have found the 1937 (and older) type clutch to be entirely satisfactory.
To install the 1938 clutch you would need a flywheel, bellhousing , starter, linkage, fork, and the transmission main drive gear and front bearing retainer.

I changed mine and did not need to change starter or main drive gear.

Then what suppors the throw out bearing on the front of the transmission.????
I would suspect your parts already have been changed over.

All I needed was to change the retainer on the front of the transmission.