The four digit height stuff has always confused me. Here's what it all means.
Digit 1 - Feet
Digits 2 and 3 - Full inches
Digit 4 - eighth measurement. 1 = 1/8, 2 = 1/4, 3 = 3/8, 4 = 1/2, 5 = 5/8, 6 = 3/4, 7 = 7/8.
6002 = 6' 1/4"
5101 = 5' 10" and 1/8 inch