Oldbolter....
Not sure of '58-'59, but in '49 the 3800's are listed as having the 5.14:1 (which is what I have). The 3600 is listed as having the 5.17 & 4.57. The 3100's have the 3.73 or 4.11.
When the cover is off....Look on the ring gear for the stamping numbers. Mine says "GM...... 7-36.." The 7-36 means 7 splines for the pinion and 36 for the ring gear. Divide 36 by 7 = 5.14:1
Update: I managed to hook up with another Bolter and am swapping my 5.14's for his 4.10's. I sure hope it is easier putting them back in!
