U joint issues

[64N53Kustomz]

Hello everyone, it's been a while since I've been able to post updates on my build because I keep running into issues. Today I thought I figured one out but not luck...here goes the story.

So my 64 c10 had a differential I could not I'd. It was way wider that the stock rear end and I could not rebuild the brakes because I did not know what rear end it was. So I bought one of a 70 pick up and slapped it in. Problem solved right? No.

When I went to attach the u joint it would not fit. Bearing cap was too big. So I had to hunt down a u joint that had two different size bearing caps. After digging through autozones selection i found a u joint that has the two sizes I needed. Success right? No.

Now the bearing cap is too wide. So the u joint on the drive shaft needs to be a bit bigger than the one on the yoke. See pics below. 3 1/2 is the yoke and 3 10/16 is drive shaft.

Finally my qyestion. Is there a u joint that will have different width and diameter bearing caps? Or am I left to change the yoke or the drive shaft?

Also, I am not 100 percent certain the rear end is an actual 70. I looked up the casting but i has a long range of year applications. Tube casting does not match the codes I found online. Can anyone help with id. Thanks!

Jorge