Joined: Jan 2010
Posts: 9,831
Likes: 1,809
From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
I'd be strongly inclined to use the bb that came out of it. Should last another 30k miles or so.
I've also put 107X70 Shimano bb's with these cranks to give a more-favorable chainline. You'd need just a couple of extra millimeters of clearance between chainstay and the little ring.
The neat thing is that every time I've ordered a UN5X bb in the 70X107 size, it came with metal cups instead of the plastic cups pictured in the catalog.
The taper on the Dura-Ace road spindles is identical to all normal Shimano JIS spindles. I've measured at least a hundred spindles of every type of fitment.