I have a 66' L60 and I have figured out that I have a T-170 rear axle but I cant find anyway to tell what the front is. It seems there are 4 different options f-050, f-070, f-090 and f-110 but I cant find anywhere that lists any specs or how to identify them. Is there a marking somewhere I'm not finding or is there a chart I can use to help match it?