This is my opinion based on my experience....for years, whenever I greased my old Ford,- I'm big on lubrication, not so much on polishing the paintwork, I'd just pump the universal joint housing full of regular chassis grease, whenever I did my routine lubrication, at least every thousand miles as per Ford recommendations, normally more often....after reading on here about JD corn head grease, I started using it. My opinion: use whatever, whenever I've stripped the old Ford at back of trans, the lube has resembled a semi-fluid grease anyway, on account of the oil that migrates through the rear trans bearing into that area and mixing with the chassis grease.
Basically, any lube is better than no lube, these old Fords are very forgiving, just keep it well lubed.
A common question on here pertains to which is the best engine oil. what is the answer?