I just got a 1949 3600 yesterday so that makes me as newbie as possible! I've been doing a ton of reading at this great site and I was planning to do the C20 differential swap.
I wrote to Patrick just in case to see if he had the ring and pinion (a man can dream)and Denese wrote back saying to use the Ford differential:
"We have not made the ones for the 3/4 ton. However, the Ring and pinion from a Ford 3/4 ton or 1 Ton Econo Van 87-93. The casting number is E5TW4210BJ. This information came from the Hollander Manual which is the bible of interchange. This will give you 3.55:1 ratio. It works beautifully. Danese Dykes"
I found two mentions of this in the old forums but no one seems to have done this so I'm wondering, will our axles mate up with the Ford? I.e., is it a straight swap like the 1968-1972 Chevy or is more involved.
Thanks and thanks for all the knowledge you have given me.
George