[davepl]

If it mics out good then it must be an assembly issue. I'd pull that apart, clean the hell out of all surfaces with a LINT FREE cloth and lacquer thinner.

Even a speck of lint can be a problem when you're talking about clearances like that. You can swap bearings like willis mentions too in order to try to narrow things down.

I prefer the rod-bolt stretch method for one good reason: when you know the initial length and you see it "overstretch", then you know the bolt is toast. With the torque wrench method you don't really have a way to know (maybe super-experienced guys can tell from feel, I don't know).

However, I don't like your clearance specs. I'd never go under 0.002 and the specs I can find are 0.0020 - 0.0025. You might starve splash-lubricated parts like the cam with clearances so tight.

The numbers you're quoting, 0.0010 - 0.0025, sound a lot more like rod bearing side clearance. Is it possible you looked at the wrong line/column in your specs?

FWIW when I had one that was too loose I swapped in a one-thousandth smaller bearing shell but only half. I didn't know you could do that but many builders confirmed you could (obviously not with a big difference between the two bearings and the bearings must be otherwise identical). It allows you to change in smaller increments than the next size bearing.