Connecting rod bearings

[od-gmc]

I am in the process of rebuilding my engine and have obtained some NOS Michigan connecting rod bearings from my local NAPA (yes, they had them hidden away in the basement). Their old books say that these bearing fit the 40's vintage GMC 270 engine but when I measure the width of the bearing it is approximately 1.23" vs the bearing removed from the engine (French) is 1.34". I have a second engine that has the same 1.23" width bearings. This being said, my question is are these ok to run? What are others running?

Thanks,

[od-gmc]

I have discovered some more info on the rod bearings. GMC made a change to the 270 engine in 48-49 (not sure exact timing) by narrowing the rod and rod journal to strengthen the crankshaft. I was able to locate the original wider bearings but would like to know if anyone has had experience with running the narrower bearings. I see no reason they should not work but the second engine I dissembled had extreme clearances on the rods but it appeared to be from an incompetent engine builder (found many other assemble problems in the engine).