Stock has some advantages - they hold thier value, they cost less to build, they work, and you know when you are done. You can't say that about a hot rod.
If the car is way too far gone from stock and you don't mind giving up some or all of the above then go ahead and mod it. You might even be able to avoid cutting it up with some effort. Many cars will cost more to return to stock than they are worth for resale.
-Mark
You get to choose.

-Mark.