New with 55 ford custom f100

Hi guys. Been reading up on alot of info here and thought id join! Just bought a 55 ford f100. Has been restored once in the early ninetys but was a hack job. Sat in a barn for the last 13 years. Currently stripping it down. Gonna do a crown vic front end swap. Got lots of info from this site ( Thanks to everyone). Has a ford nine in with the 5.5 bolt pattern. Got a line on another nine inch with 4.5 bolt patter to match the front.

First question i will ask is.. Anyway to tell what gears are in the rear without having the tags? And without dissasembling the pumpkin.Any thoughts would be greatly appreciated.

 

Hi. Jack up rear end and put a mark straight down at bottom side of tire & as bottom of drive shaft. Then with tranny in neutral rotate the tire by hand. The gear ratio will be the same as the ratio between the # of turns on each the tire & drive shaft.
Example will be if you have a 411 ratio then one will make 1 revolution while the other does 4.11 revolution.
Good luck, Jim