Need ac help

[Ozark Tim]

So I had to purchase a new accumulator for my 71 gmc
The female threads on each side are the same but....
The old one (and it does not look original to me) has a slightly larger size opening on the condenser side than the evaporate side
I also notice that there are 2 pipes with a union between the accumulator and the condenser coil. My other ac truck is a big block and it only has 1 pipe with no intermediate fittings between the accumulator and condenser coil.
I suspect someone replaced the accumulator and modified the tubing but I have no reference