Well, Beezermacc was typing at the same time with some good advice beyond what I have here, but since I'm not contradicting in any significant way, I'll go ahead and post (having completed the thumb typing).
Since it costs no more, I would go with a -0.020" new bushing. I think this will put less stress on the machinist rather than starting with a sparce 0.007" to work with. This is how I see the numbers:
1.366" (timing-side OD) + .001" (bearing clearance)= 1.367"
If -0.010" bearing: 1.367" - 1.36" = 0.007" (to remove to match the crank journal)
If -0.020" bearing, then 0.017" to machine down. Of course, the machinist should know or be told to clean-up the journal (it seems grinding may not be needed, or, at least, not much), then ream the bushing for 0.001" clearance with respect to the journal, not according to the bearing's undersize rating (with no more than 0.0015" clearance, but you know that).
As always, and for good reason, I stand to be corrected and wear the dunce hat if this is proved to be spurious advice.
Richard L.
(I made a small edit, in light of Beezermac's advice.)