Center link-idler arm gap
 

Would this concern you? Putting brand new everything up front. The center link is from Rare Parts while the idler arm is from OPGI. The idler arm mounting flange on the new one is 1/2” thick vs the factory 3/4”. So as you can see it appears that it’s not sitting all the way down, but really it’s just a thinner flange, if that makes sense.

I sent pictures to Rare, just to gauge what they would recommend and they are the ones that mentioned the flange size. Told me it would probably be fine and to just add another foam ring to help keep dirt out. I trust his knowledge over mine, I was more curious if anyone else has ran into this? I also attached a photo of the pitman arm side so you can see how it sits flush on that side. I mentioned to the RP tech guy about reaming the idler arm, but as he pointed out then my cotter key hole would probably be above my castle nut slots. Both sides have the cotter key hole lining up well in the castle nuts as it sits.

It’s on a 66 Catalina Wagon. I also emailed OPGI, but waiting to hear back. The bag for the idler arms says it’s correct, 63-70 Full size I believe. Thanks for any feedback!

It's the taper that seats the joint, not being pulled up tight against the arm. If the taper on the ball joint matches the arm, and the nut tightens up properly, send it.

If the car sees road salt and mag chloride, you may want to protect the ball joint, but otherwise, you're good to go.

As long as you're positive there is no bit of debris inside preventing the taper from fully seating your good. It's common to run raised joints to compensate for bad factory suspension geometry. See photo.