Male threads of that size have more than 0.002” tolerance on the OD of the threads.
Pitch diameter is difficult to measure without special tools.
Pitch diameter is a tighter tolerance and much better data point for determining correct size of male threads, or if it’ll fit a standard size tapped hole.

I wouldn’t assume the new parts are out of tolerance by measuring the OD and finding only a 0.002” discrepancy.
0.002” is half or less the thickness of a standard hair.

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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