Outer Limits 4x4 Board

how do i id the year of the front axle/knuckle.

i need to do a knuckle rebuild, but apparently there are pre 1975 types and post 1975 types.

I am almost certain that my 40 has had an axle swap in the past. How do I tell what type it is.. heres some pics

and are 45 and 40 knuckles the same...

http://cgi.ebay.com.au/ws/eBayISAPI.dll ... 2455675751

pull the short axle out and if its a bifield it will be post 75