When I hear myself saying it in my head, it’s seems pretty obvious....... to me at least.

You wouldn’t install a new crankshaft without measuring the journal sizes...... would you?
And if you didn’t...... well you could still plastigauge it.

Of course, plastigauge isn’t an option for a full round bearing..... so at a minimum you’d want to at least measure the journals and make sure they’re to size.

Same goes for straightness. I always check it...... on cranks and cams.

Factory BB Mopar blocks are fairly notorious for having screwed up cam tunnels........ so when a cam won’t go in, it’s 50/50 which is the culprit. If the cam is straight and to size..... the problem is the block.

In cases where one cam fits where another doesn’t....... its a safe bet the problem is the new cam.
But..... you gotta measure it to know for sure.