I was a die hard GM fan. Even named my male cat Chevy. After I test drove a 2011 5.0 I knew I had to have one. For the most part, I hated Mustangs prior to that. I think the 401a interior is pretty nice. It is comfortable and functional. Only thing I dont like is the cup holders in front of the shifter. If you plan on DDing it, I would suggest a couple of things. First is weathertech floor liners. Second is a MGW shifter and AMSOIL MTG trans fluid. The MT-82 is a pretty good trans with those improvements IMO. Once you learn the querks, it is very pleasurable to drive. The gearing is a lot of fun to drive hard with 3.73's in the ass.
I like the 11-12' front end better but the 13-14' rear looks better IMO. I think there are minor changes in the blocks through the years. Not entirely sure what though. Best car I have owned to date....Do it.