74 Duster inner fender replacement

I'm replacing both inner fenders with AMD and am having a bit of a fitment issue on the right side, I'm doing them one at a time. I will have some pics on later but the issue is in the rear of the fender where it is supposed to line up with the cowl edge. If I line it up on top, there is a large gap on the bottom where it welds to frame rail. If I close the gap down on frame rail, it sits over an inch away from lining up with cowl. From what I hear about AMD metal, I would guess that my car is that far out of square. When the inner fender is down tight on the frame, it looks like it is supposed to, I'm just wondering the best way to make it fit, like do I need to shrink down the edge where the old inner fender was so it lines up with the AMD replacement? Thanks for any input.