I think it is a good axle and the 9.5 differential should hold up to longs better than a v6 or hi-pinion. I have heard that the rear elocker differential in a fj80 will fit in the fj60 with slight modification. If you look long enough you can find them in junk yards for not to much. The only draw back to these axles is that you decrease ground clearance by about 1 inch.
Your rear differential and axle shafts would be the weak link if you like the skinny pedal. If you end up breaking your rear axle you could always build a full floating diamond axle with a fj80 rear differential, disk brakes, and use the fj80 factory e-brake. Here is a good read on what I am talking about it is under a fj cruiser
http://www.pirate4x4.com/forum/showthread.php?t=704382 and it also has side by side comparison of a mini truck differential and a 9.5 differential.
Here is Zuks take on the 9.5 vs 8.4 tacoma differential
http://board.marlincrawler.com/index.php?topic=59683.0;topicseenA pair of 9.5 would make a strong set of axles, getting a lot closer to 1ton strength than the mini truck axles can due to their small differentials.
Hope this helps you out.
