1968 904 in a 1963 Valiant with 7 1/4 Driveshaft Length

[xLURKxDOGx]

Does anybody know what the length would be because i cant find any helpful information on this and the best ive came up with trying to measure myself was 52-52 1/2 center to center. I grabbed one from the junkyard and it turned out to be to big at 54 1/2, so if i can get a ballpark number other that one person trying to hold a tape measure under the car than i can go poke around tomorrow.

Thanks,
Jake