I agree, if its not performance mods being the reason to tear it apart then the old saying comes to mind.... if its not broke dont fix it

 

Modern cars, properly maintained should go 200,000k miles easy (pending the body does not rot away). Unless the engine has internal problems (like connecting rods, bearings, and such).

The 3400 and 3800 is no exception, they can go at least 200,000 miles and beyond.

If it's not for a performance mod reason, LEAVE IT. Odds are you'll throw good money away otherwise. If you are having some issues, let us know and we can try to help.