Disregard.

If you can, I would send them back.

You would bore them to 0.0055 GREATER than your crankshaft measurement. Standard crank should have been 3.500 so an unworn crank would take standard bearings that measure 3.5055 ID

If you do bore them, I would take the time to measure the crankshaft journals and bore to minimum clearance.

The rod bearings and journals would be as high on my list to return to spec as the mains. I’m sure there have been engines that failed because of the main bearings being worn but with them being doweled in place, I’m betting it’s almost always a rod bearing that goes out first.

Thanks OM for the part numbers. They cross over to the 4F numbers for the 9U so we are on the right track for bearings. The only bearings available in Standard Size are the front and rear bearings at aftermarket prices. Looks like I will be boring the set of .030 bearings I have to .005 over journal measurements. Should be interesting.
ccjersey The rod bearings looked really good when I put this motor together, and no more use than this motor will get I think they are going to be just fine. The rear main was the culprit leaking is the only reason they are getting new bearings although they are worn way over specs.

I finally got the 1V motor fitted into the 5R D6 frame and hooked up. Dry Clutch with the housing bored for starter. Everything so far has been a bolt for bolt process. Used the 5R radiator ( the radiator and fan are not as close as with the 4600 motor) and dash panel, just haven't figured out how I am going to do the air cleaner. There is room under the hood to put a dry air cleaner, but that would mean removing the hood to service the air cleaner. Do not want to use the 9U style air cleaner because it would block the dash with the gauges in it. Wanted to maintain the 5R hood and dash. I haven't started it yet to see what kind of power improvement there will because I am trying to rebuild the fuel system to make the motor start better. The individual pumps (4F6921) are leaking down making he motor hard to start. (loosing prime in the fuel system with insufficient pressure) I have had the motor running on a stand with a radiator so I know the motor runs. There was a difference in the lower radiator fittings but was able to hook connect them with a 1 3/4 inch to 2 inch flexible radiator hose. The fitting in the 4600 radiator was smaller so I hope it doesn't restrict the flow enough to make the motor run hot.

oops, double post, please remove.
Cheers,
Eddie B.

Hi Team,
fan blade position should ideally be around one half the blade width inside and outside the fan shroud for optimum air flow ability. A suitable fan spider spacer should get you there.

Loss of prime in the 4F6921 Injection Pumps would likely be an air leak up in the top of the Fuel Filter tower area--faulty cover gaskets, cracked cap or spacer plate, leaking Tower air Bleed Valves etc. as the fuel level in a low/partly full fuel tank will likely be below the top of the tower and Inj.Pump level.

Cheers,
Eddie B.