@ Ultra, the SD Headers come with the U-bend replacement, and without removing it you aren't helping yourself by buying headers, if you don't aim to remove the u-bend just stay stock.
RACING MANIFOLD HEADER/EXHAUST GRAND PRIX/GTP/BUICK REGAL/IMPALA/MONTE CARLO 3.8 | eBay
As far as taking it to a shop... why? Pocket the cash and put it you use somewhere else. Basic tools and Mr. Billboost37's handy dandy guide and you will be in and out and through a 6-pack before you can say Torque-Wrench.
http://www.grandprixforums.net/how-install-headers-easy-method-44126.html
You only really have to worry about the downpipe SD have if your lowered and even then pay attention to where u drive and don't take high speed speed bumps and you'll be fine.
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