What is the factory rod bore diameter on a 1972, 400 small block 5.565 connecting rod? All I can find anywhere is the info on the change to large journal 2.1 rods. I want to know what the size of the bore is, without the bearing, not the size of the crank throw/bore with bearings installed. My reason for this is that I have some old parts and need to determine what they are. I measured the rod bore at 2.224 – 2.225. These rods have been reconditioned, and I'm not sure how much the bores were changed, or if they were just honed a little. I plan to sell the rods, and need to be able to describe what I have. I also have some Clevite bearings, P/N CB-663 P, which I bought without yet having the crankshaft for the motor. I have found that these are correct for the 400 SBC, but the same number appears to be used for undersized bearings, as well, with customers simply specifying -.010, etc. when placing an order. There is no marking on them to identify them as standard or undersized, just the basic part number. Can the application (meaning standard or undersize) of these parts be determined from the information I have: 2.225 dia. with P/N CB-663 P? I would rather not measure the thickness of the bearings because they are still in sealed packaging, and I plan to sell them also. I am afraid of losing buyers or money by opening them, but I will if that is my last resort. I didn’t know if measuring their thickness would even help, because the bearings are designed to crush a little as things are assembled. I would have to know what this crush is in order to get my final diameter by subtracting the bearing thickness from the rod bore diameter. It is interesting to note that subtracting a standard .125 from my measured 2.225 gives me exactly 2.1. This leaves no room for bearing clearance or “crush”, but seems to indicate that the fit will be on an undersized throw. How much do those bearings crush? Can I tell what the application of my bearings is by measuring their thickness? Help!
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Actual rod bore diameter in SBC
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