Is there any difference between the factory auto-sears on an AK vs an AKM?

Yes, they are different. The AKM auto sear has a curved trip arm with a small sear trip surface, while the AK-47 auto sear has a straight trip arm and a much larger sear trip surface.

Despite the AK-47 auto sear's larger trip surface, the actual engagement area between the hammer and auto sear is the same on both the AKM and the AK-47. This is due to the hammer's auto sear contact surface being the same size on both rifles. In fact, the AK-47 and AKM hammers are practically the same, with the AKM hammer having a small radius where it contacts the hammer retarder as the only notable difference.

All AK-47 auto sears are machined steel, as are most AKM auto sears. Some AKM auto sears are stamped steel.

Thanks. I tried to do a Google search, but all the answers involved the difference between SA and FA FCGs.