Do Clevite bearings have a upper and lower rod bearing? I removed the stock GM bearings out of this 1986 454 and they were marked upper and lower but I see no markings on the Clevites I bought.

some do and some dont,bottom line is both upper and lower are the same.

Not the same on chamfered bearings for aftermarket cranks that have large fillet in rod radius,be careful with this the rod cap will go on and will allow proper tourqe on rod fasteners but if installed wrong u will not have proper big end rod side clearance and will tear up edge of bearing fast

Only the performance "H" bearings have uppers and lowers. Were the stock bearings actually GM parts ? If so is there a GM part number on them ? Do the replacements look like they are the same width as your originals ? What engine is it ? In 30 years I cant say that I have ever seen a GM engine with upper and lower on the bearings but there is always a first time I would be very careful to measure everything with the replacements.

Thanks Miced both old and new for width and thickness and they are identical as are the two halves.

Thanks Mike.