Just off the top, the final drive cases and some associated parts outboard of the steering clutches are different. Also the transverse spring. I think everything else is the same.
As Stephen says, and you can basically state it as anything that gives it width, which pretty much boils down to certain items in the final drive/steering area, along with the main spring. So for example, the final drive pinion shaft is longer (supported with three bearings instead of two), but the clutch hubs, and mechanism are identical. The central transmission case is identical etc. The final drive housing is wider but the final cover is identical, as is the final drive driven gear and shaft. But pretty much everything else is the same. So there's actually not many parts that are wider.
The pivot shaft, forgot about the pivot shaft, it's longer also.
Thanks guys. Helpful people here are a motivator for people to join the club, which I did yesterday. I enjoy forums where the dialog is helpful to people. As many of us know, there are plenty of forums on various topics where a few people banter back and forth and try to degrade each other. Those sites are easy for me to ignore.
I look forward to getting my first ACMOC magazine.
Greg
Well done Greg, thanks for helping to support the Club, good luck with your 5J restoration.
Mike
The pivot shaft! I'm glad the boss didn't send me out on the job to convert a 3J to a 5J - I would have forgotten a key part, which is the story of my life. Every job around the house requires 3 trips minimum to the hardware store : )
By the way Greg, did they tell you that membership requires mandatory posting of photos, progress reports, and a detailed youtube of the first start-up : )