BE3 Input Shaft Shim

[ally406]

I rebuilt a BE3 box with shafts from a donor box. So an admission of being lazy, I whacked it all together without paying much attention to input shaft shimming. The box has the original shim installed. The input shaft bearings whine considerably which I assume will be due to incorrect shimming. I'm struggling to find any documentation on this, apparently it's in early 205 Haynes manuals? Can anyone offer some quick guidance so I don't need to wait on Haynes manual in the post?