Replacement Exhaust Manifolds?

[307 Regal]

With the sorry state my exhaust pipes were in, I fabricated a simple glasspack exhaust system for my Regal last night. Although that eliminated all the rotten pipe from the manifolds back, it did not eliminate my problem. I still have exhaust leaks somewhere. :\
Unfortunately all that's left to replace are the manifolds and I have no idea where to find replacements other than maybe a muffler shop. I've got a couple questions / ideas and I was wondering if any of you could help:
*note: it's a 307 olds
- would auto zone / advance auto parts have exhaust manifolds?
- can I find better flowing manifolds from an older model Olds v8 and fabricate a dual exhaust?
- where can I find those?
- would it be better to install "shorty" headers?
- if i didn't go with some cheap headers, would welding be unavoidable?

as far as additional info goes, all exhaust related emissions/catalytic converter equipment have been removed so I'm not worried about that. Any opinions or knowledge would be much appreciated. Thanks in advance.

 

[87BlackSheep]

For $200 you can get a pair of flowtech longtube headers (you can order them at autozone, advance, etc) for your 307, and a pair of glaspacks for $25 a pop. They're real easy to install and you would get better fuel economy and much much better exhaust flow than stock manifolds. I posted a thread about the installation here: http://gbodyforum.com/viewtopic.php?f=13&t=20552 plus a video on youtube: http://www.youtube.com/watch?v=j2_69MnHiQs

 

[454muscle]

Dude find out if these headers will fit. I just saw this thread, ceramic coated Flowtech headers, summit sells em for $279 + shipping but this guy has dropped price to $200 shipped so it's a great deal. I'd get em if I needed it.. LOOK:
viewtopic.php?f=31&t=23960&start=0

Flowtech part number in the post

 

[87BlackSheep]

Here's the headers I got on mine: http://www.summitracing.com/parts/BIG-11152FLT/

 

[Blake442]

Unless they're cracked, exhaust manifolds rarely need to be replaced.

I'd check the air tubes going into the exhaust ports in the heads, just above the manifolds, for leaks before I did anything else...

 

[307 Regal]

Unless they're cracked, exhaust manifolds rarely need to be replaced.

I'd check the air tubes going into the exhaust ports in the heads, just above the manifolds, for leaks before I did anything else...

those holes have been plugged. btw, idk what the 442 system looks like (was it basically dual exhaust?), but my driver's side exhaust runs under my oil pan and goes up into the back of the passenger side manifold, and then it goes down to the cat area as one tube. there are a couple gaskets invovled with that I could check (or try to).
454; I'll check that link in a sec.
Black sheep; I'm really considering the glass pack idea. i've already got 1 on there and i've always liked the sound of them.

Thanks guys.