I have wrapped mine but my pipes are not stock, I used the stock headers cut em off and welded tubes on. The stock heat shields and mufflers are mainly just clamps that are screwed on. Im thinking by the "some pieces welded to frame" you might be referring to the goats belly where all the exhaust collects. This is basically a joint in the pipes again should just be screws and clamps. If you're exhaust is stock theres really not any need to wrap because the only part you could wrap is the headers. Then the heat shields etc will not fit.
Malteese led Turn Signals (Rear)
Paid 750.00$ for her in 2005 w/ 9k
Currently @ 23k and counting