Originally Posted by Danthurs
I believe speeddaddy headers are the ones on ebay. And if memory serves these are the pacesetter knock offs and there for bolt right up with little modifications. Down pipe I think, Transmission dip stick tube will need to be change to a Wbody tube, and possibly a little modification to the front trans mount, nothing major.
What jake above said. They're SLP knockoffs. Actually, they're SSAC knockoffs, which are SLP knockoffs, lol. However, they are built VERY well and its stupid to buy a front plog for this engine when these headers are $205 shipped!!! Anthony on here has a set, and the guy who'* doing my L67 swap said that these are very high quality headers. These are the real deal.
Otherwise, what everyone has said are excellent suggestions. Do NOT use loud mufflers on these cars unless you have an array of modifications. These cars sound like complete crap with loud chambered mufflers on an otherwise stock engine. If I were to describe it to you, they sound like a chainsaw in a blender.
The following video is with headers, no cat, no resonator, and no mufflers, to give you an idea of the kind of chainsaw sound I'm talking about.
Keep in mind he has headers and it will sound worse on a car that doesn't.
Magnaflow mufflers will work well, along with headers. The latter will provide you a decent boost in performance as well.
2005 Pontiac Bonneville GXP - For Sale ----- 1995 Buick Regal GS(X) - L67 madness
2000 Buick Regal GSE - Stock...for now
----- 1987 Jaguar XJ-* V12 - 12>8