The main in-dash head unit can be swapped without any problems; if you want to replace the Infinity amp & speakers, unfortunately, it's not a bolt-in swap. There's no wiring for the Infinity amp, no wiring in the dash for the tweeters either. I had this brainstorm that I'd do the same thing you're speaking of, but it didn't work out. I was totally surprised to discover that DC actually used a different wiring harness in a RAM that has Infinity versus one that does not. Hope this helps !
Greg