Well...My intent was to stay simple, but this project has snowballed.
After some thinking, I've decided on independent rear suspension! For a commuter restomod, I decided I wanted something different then leaf springs. I was looking at a 4 link setup, a 2 link/panhard bar setup, and IRS.
I part out SRT8's for a weekend gig and I have several complete IRS setups laying around. Matt set one up under the car and decided it wouldn't be too crazy to adapt. He had been contemplating doing the same thing to his wife's car so he's been thinking about it awhile. Ultimately we decided it would be worth pursuing.
I love the way my 2010 Challenger SRT8 handles/drives so that helped greatly in the decision. The K frame will need to be shortened 2 inches in the middle and the original mounting pads will need to be cut off so the IRS frame can slide between the Roadrunners rear frame railst. This is the IRS K frame before modification:
First thing, the K frame was reinforced/boxed in a few areas: