[Orange97GTVert]

When I first got into Mustangs, the rule was if you modify it you are going straight to hell. Mustang Monthly cranked out month after month after month of perfect restos. That was in the 80's. I grew up in the 60's, nobody left a Mustang just like it came from the dealer (kinda like now!) and the hobby has grown that direction. It is your car, do it your way. Unless it is a Vert or a Fastback or a Shelby or something rare you can do it your way, you won't hurt the resale that much, chances are if you swap in a V8 it would be more desirable ($$) than the stock 6 anyway.