At one time you had to send Aviaid your original pan in exchange.
I have only installed two of these pans. Aviaid on the Pantera, and Canton on my 68 Shelby.
I used ARP pan studs on both and used flanged hex nuts on both.
Both pans needed to be jacked up into place on a floor jack and then tapped down into place.
I may have enlarged the holes in the pan slightly as well.
Considering that they are gas welded on relatively thin gauge sheet steel, I'm not shocked that either need to be fit.
I would expect that from any of them.
As the expression goes, "there is no such thing as a true bolt on!"
I've seen worse. I had a set of JBA headers for the 68 Shelby that I paid $995 for. They were absolutely beautiful out of the box and fit perfectly, sort of... except for one little thing...the pitman arm hit the #5 tube and as a result the car couldn't turn left. OOOPS!
Oh, and the special z-bar they made for this setup, it didn't fit either.
Don't buy JBA.
Well they refunded my money, but I had to pay to ship them back AND they blamed the RETAILER and took the refund out of his account.
I have a ball peen hammer here just for explaining things to them. I just love to meet with factory Reps.
I guaranty they won't pull attitude on me EVER AGAIN AND SURVIVE...PROMISE! Don't worry, even if they do survive...they don't remember a thing...especially their own names. Something to do with experiencing sudden impact?
The retailer used different tactics. He dropped the entire JBA line.
I would recommend the Aviaid pan for the Pantera or the Canton for a Mustang for that matter. Issues for either are relatively minor. Both are excellent quality.
The Pantera pan hasn't come off since original install but the Canton has. On re install the Canton went right back on. None of this twisted/misalignment of the original install.
It took the proper set after running the car.
An aluminum pan sounds nice, but around here pits even just sitting in the garage. Sounds nice though. These steel pans aren't particularly light.