Sorry Pat but the only thing an OEM Ford distributor and A MSD unit share is the reluctor and basic coil pickup assembly. The MSD distibutors are far better in materials and craftsmanship than the OEM piece. The Billet MSD piece uses a sealed ball bearing in the top area and an oilite bronze bushing in the bottom for better support. The OEM Ford piece hasn't changed in basic construction in over 45 years. The unhardened shaft is supported by a single bushing and can develop quite a bit of "additional clearance" when loaded by a high volume
oil pump. Ok for stock application but leaving a lot to be desired in high performance circles.
Just my observation
Rick