On May 17th, I ordered a set of Clevite 178P-10 main bearings. The expected Shipping date was June 8th. Now, the shipping date has been moved back to July 29th. The bearings are supposed to be shipped from Clevite. On the other hand, Sealed Power M-Series bearings are in stock, and they are cheaper. 

Based on reviews, I gather that the Clevite P-Series bearings are superior to the Sealed Power M-Series, but I can't confirm it. I'm willing to wait for better bearings, but who knows how much time I have left at my age. I suppose there's always a chance that the expected Shipping date could change either way. 

Recommendations?                                                                    

I have a NOS set of Federal Mogul of 292 mains, .010 if you ae interested.

John - "The Hoosier Hurricane"

For most street build applications, the oil clearances will dictate which bearing you will use.  Assuming the bearings are installed in their respective holes and the I.D.’s are micrometer checked, then the crankshaft can be ground appropriately for the desired bearing clearance.  This would allow you to use a given set of bearings without risking the bearing clearance being outside of the parameters being targeted for.

The brand of the bearing itself is a moot point as long as an oil film is always present between the moving parts.  For journals that have already been ground or are already a specific size such as found on a brand new crankshaft, it’s not unusual to have to try different sets of bearings to get the desired clearance.  In cases like these, just getting the same brand of bearing that’s made on a different day will net you a difference clearance value.  In a heavy duty or extreme performance level, then a bearing with different construction attributes may prove beneficial.  Another option are coated bearings which tend to further reduce any friction attributes.

Lorena, Texas (South of Waco)

Thanks, Hoosier. 

I canceled my order for the Clevite bearings. Apparently they're having "supply chain issues." Maybe they are now made off-shore and subject to new tariffs. I went ahead and ordered in-stock Sealed Power bearings; they are supposed to arrive by Friday. If there is a problem, I'll get back to you regarding the NOS FM bearings.