Tom,
Obviously .0008 is way too tight!!! I think you're out of luck when it comes to .001 oversize main bearings. We can get Clevite .001 oversize in rod bearings 1398HX but Clevite and FM have never offered a .001 over main set (as far as I know).
Have you miked the journals and the main bores? If the main bores are tight, they will eat up your oil clearance and put too much crush on the bearings. If I remember correctly, the spec on the main bore is 2.6870-2.6880"
Is this for your TA build?
Dave