Tubular A arms slightly too wide!

could they possibly be made to fit b or e-body? or maybe they're not made for Mopar at all.

Nope. B/E body UCA's are over 2" wider at the mounts.

Sounds like someone unloaded a problem.

That's what I'm thinking.

They were never installed. Got them with a disc brake kit. The thing is, the brake spindles require the b body style upper ball joint so I can't just put these brakes on my old a arms.

Ouch. So, basically I'm thinking you got a set of UCA's that are out of spec. Jig was off, welder had a bad day, something. If you'd bought them yourself you could just return them, that's exactly what I'd do. Do you have a receipt from the original purchase or anything? If you know the brand of UCA it would be worth trying to contact the manufacturing company. If they're a half decent company they'll want to know, because if it is in fact a jig issue you won't be the only one with this problem.