I have a 37 Ford flathead that was burning oil and needs to be freshioned up. I have read the a lot of times the bearings can be reused. My question is other than a visible check should I plastigauge them before I pull engine apart? (I don't have mics) since the are floating do you plastigauge both inside and outside of the bearing?
Forget the Plastigage. You need to use a micrometer to exactly measure the crank pin diameters and assemble and torque the rods and caps without the bearing shells and measure preferably with a bore gage or inside micrometer. Compare readings to engine specifications to determine what size bearings to use or if you are in need of crankshaft grinding and/or connecting rod re-sizing.
Plastigage is a good place to start. Yes you would do both sides of the insert. If your in spec move on if it's just an overhaul. If your oil pressure is holding solid at around 10-15 lbs your probably Golden. If your a Shop and doing a Customer job then of course your going to do a Total tear down, do a bore job and do a total rebuild by the book. I mean ya gotta guarantee your work out the door, not just under your own Foot. That machine shop rebuild will hit your Wallet some where between 7K and 10K depending on how much you let them do. You can bring it back to good enough at home under 2K. Maybe less if your just doing Band-Aids.
28 dreyer is on the money I have rebuilt a lot of these fully floating motors back in the 50s...you need good micrometers both internal and external ...a lot of patience and write every thing you measure down as you are dealing with several measurements ie; internal of the con rod ..crank journal...thickness of bearing shell...plus the clearance..just take your time and recheck ...personally I wouldn't use Plastigage...its a very expensive mistake if the engine fails...The clearance is very critical to avoid bearing failure ...just be very patience..check check again