I checked with my supplier and he said they were discontinued but they would make a batch with a minimum order of 250. Your next option is to take a set of calipers and measure the out side size on the diff and the size of the yoke and match one up that way.
Got that done already my friend. I got the same answer, But this ol' feller already has one up on them. I found a bunch of them in the Toronto area @ $48 bucks, plus Mr. Harper's share. This fellow said they are same as originals. Late 40's to early 50's Dodge cars & pickups.
He sells them to people with bombers in Quebec, Ontario & Manitoba. Then 3 hrs. ago I got another call from Denver, Co. This fellow has them for $40 bucks plus shipping.
I was told that the salesmen nowadays use the newer books. This fellow went back to the old school & BINGO... there it is.
National # is 451350. He crossed it to an older number, 5851, & gave me these dimensions. 3.130 OD 1.750 ID 500 width. It was the same as my national #. I will order it tomorrow. I hope everything works out OK. I may be slow.. but I'm trying....
The Old Trucker