Yeah, the 3.73 would almost make 1st gear a granny gear in the 700R4, and downshifts on the highway would really buzz the engine. I wouldn't go any steeper than a 3.73.

I have a 700R4 in my IROC Camaro with a 3.42 rear end and that's about perfect for a street car. I cruise at high speed at around 2000 rpm and it has plenty of get up and go in first gear to make a 3200 pound car feel light. So you could even go taller in your gearing.

Perhaps you can emulate that with taller tires on your 3.73. Or put the short tires on it and have one helluva quick little truck.

52 GMC 3/4 ton pickup
68 Big Block Vette
68 455 Firebird