there is a small u-joint,a big u-joint,and a bigger u-joint,that is like a ford yoke...look it up for a 67 polara 440HP/426 hemi..kinda odd ball...the common one is a small to a large mopar joint like in trucks...the odd ball is 3 5/8"

I am running a conversion joint small on one side an 3 5/8" on the big side

caps are bigger round and the yoke has tabs to hold the big side caps in

measure the yoke inside tab to inside tab to get the right one

crosses over to the mopar/ford u-joint,caps have no grooves for c clips on the big side

got it at napa,I will get the # off the box later for ya