The Federal Mogul shop specification catalog #115 lists the main bore as 2.4906"-2.4916". Yes, it needs to be round, within those specifications. Are the mating surfaces perfectly clean, and are the bolts torqued while taking the measurements? Side to side dimensions aren't as critical as top to bottom, but a .002" difference is pretty extreme. I usually ignore the dimension at the parting line and rely on a vertical measurement, and one at 45 degrees from vertical both ways. If those are within tolerance, press on!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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