U Joint sizes: 71' Duster

What came stock in the following:

a slant six 71 Duster with a 904

I am STILL in the middle of my 8.8 ford axle conversion, and have swapped out the /6 with 904 to a 318 with 904... I probably won't be able to use the stock shaft, and probably wouldn't want to, but just for conversations sake, what size u joints do I have now? Are they possibly 1310's or 1330's?

What do stock 71 Dusters with the 904 come with? I will probably convert to whatever size these came with stock..

Thanks for the help in advance?