Thanks Guys, and yes its IRS thats why I want to go with it. I love the handling the Tbird has and want the same safety with the plymouth. From the looks underneath the Tbird it doesn't look like too much more work, but then again the hardest things always seem to look easy for me until I start them.
I am also thinking of using the A arms for the front if they will bolt up to the mounts already on the plymouth. as the mounts look like they are built into the frame and I don't want to graft a front clip on at this point, Unless someone knows of a rotor that will bolt to the original A arm.