[Synchro909]

I don't use Plastiguage any more after I found I was getting too many unreliable readings when the engine was in the car. That was mostly due to my technique. The weight of the crankshaft gave false (tight) readings. When the engine is out and upside down, fine but not in the car.
The aluminium foil my wife uses is 0.0005" thick so 3 layers is just right. I also like a piece of newspaper (if you can get it these days) but that technique is slightly different. Examination of the paper after tightening the bearing cap tells me a lot about the clearance - too tight/too loose. I'll explain that later if anyone wants to know.
With all bearings backed off, the motor turns very easily (spark plugs out). I put 4 layers in the bearing, tighten and try turning the crank. It should be too tight. When I put 3 layers in and it turns with a little drag, I'm happy. If the crank still turns easily, the Bearing is worn so take out a shim and repeat till you feel a drag with 3 layers. Once you get that bearing right back it off and move to the next. Don't be impatient and do only one bearing at a time. Doing all 7 bearings properly takes time.