This is for a 79 correct? In a previous post you werent sure. The first VIN digit will be a 9 if it is a 79. As for the engine in it now did it come with the car? If not what is the 5th digit in the VIN? If its a T (straight 6) that may be the problem. I dont think the K-member for a straight 6 works with a 302, even with 302 motor mounts.

If thats not the problem then something has to be bent, or you got ripped on those mounts.

For a 79-85 youll need a new trans cross member (doublehump) for a true dual exhaust, and a few hangers for the other muffler/tailpipe.

 

If you were close you could borrow a set I have 2 sets sitting around some polyurethane ones and stock rubber ones