Challenger looks much tougher with the wider tires you added. Good to see a dark green car, so many of those are now red, black or purple. The silver billboards are striking on your blue 71 Cuda. Great looking cars!
If the 383 is numbers matching for the Cuda? If so, I can see why you might leave that in the car instead of installing the 528 Hemi. Then again, you can always pull the 383 and put it into storage so you can enjoy it the hemi.