Yeah I've already called AMD, I don't remember the exact measurement off hand but I know their kit is for the 2 door non post, which is 2" shorter then what the 4 door/2 door post cars need. You maybe on to something there with the B body lengthed trim. I'm going to dive into that to see if it'll work.
And after looking at the pictures it was the top I had to shorten where it goes under the overlap. I just used a Dremel cut off wheel and filed the burrs so it slid together nicely, can't see it anyway.