Justin,
Below is a link to a u joint on Ebay that will fit a 4 spd in your '37 truck.



http://www.ebay.com/itm/Universal-U-Joint-Assembly-1937-1938-1939-Chevrolet-Chevy-Truck-GC-HC-JC-/311711388353?hash=item48937252c1:g:VmMAAOSwAuNW7Q5m&vxp=mtr


1937 Chevy 1/2 ton
1942 Chevy 1/2 ton
1947 Diamond T Model 509
1951 Chevy 1/2 ton
1950 Chevy COE Model 5700 ~ "Barney" ~ And more pix