Teeka56

I'm tired of my headers on my '73 SB. Is there a cast iron alternative that isn't too restrictive on power? I seem to recall that all iron manifolds are not the same or that someone had a HP version that offered better flow. I'd like the 383 I'm building to look stock and be a bit more quiet. Thanks in advance.

noxqsz

Teek;

There are 2 1/2" (as opposed to 2") outlet "rams horn" manifolds that were installed on some mid-year Corvettes, and you might come across them now and then, but they will be expensive. There is also a company called Sanderson that makes freer flowing cast iron manifolds, but they're also expensive and I've never much cared for the way they look. Like you, when I bought my '73, I quickly tired of under-car clearance issues and the blown gaskets and having to remove the header to remove the starter, etc. etc. When I installed my 400 small block, I replaced the headers with ceramic coated stock exhaust manifolds. Grand total was $300. No leaks, no clearance issues, look great, no problems. My opinion is that for street-driven cars that seldom see 5K rpm, the performance difference between tubular headers and cast iron manifolds is so insignificant as to be non existant. My 406 doesn't seem to mind them at all. There is one more alternative I forgot to mention. There is, or used to be, a company with a process called Extrude Hone that would, in effect, polish the inside of your cast-iron exhaust manifolds to make them freer flowing. I don't know how much it costs, but I'd guess it isn't cheap, either.

I know there are lots of others on this forum that will disagree with me about headers vs. cast manifolds, and I have the utmost respect for their opinions. But I'd never go back to headers. By the way, I'm also a Washington state Corvette owner, but on the east side of the mountains, in the Yakima Valley. The Corvette club in Yakima puts on a show every year in June that's a lot of fun, and that several cars from your neck of the woods come to. Let me know if you're interested when spring comes around!

lbell101

Tom's got a set of the low horse 2" Rams Horns from a '71 for sale over on the parts board. Very reasonably priced too.

randy72

extrude hone is about $500 for the set. It will make them flow beter and reduce their mass. Pick up November 01 issue of Musclecar Review if you can (it's since been cancelled) and there is an article on my bro-in-laws Hemi Challenger before and after extrude hone, with dyno results.

ORVette

I have a pair of Sanderson cast iron exhaust manifolds on my small block. They are 1 1/2" primaries into a 2 1/2" collector. They fit real nice and look good, have a thick flange and seal up well. I can't remember their webpage address offhand.

ZD75blue

port an polish, port match, and smooth the inside of the pipes... also see if you can hog em out a little.... there is a company... forget the name, that cnc ports exhaust manifolds

:seeya

Jughead

Do they mate up to a stock Vette exhaust?

Steve Grodin

The 2 1/2" rams horn exhaust manifolds are available from Chevrolet.

ORVette

These are the only pic's I have now. I don't know if they'll bolt up to stock pipes because my car had a new 2 1/2" system custom installed before I bought it. I bead blasted them and treated them with a manifold dressing my friend makes at home. They really look good.

69L71

You can still buy the 2 1/2 inch rams horns from Chevy. What you're looking to do is replicate the exhaust from a 65 327/350. I have the part numbers at home. You'll need to grind away a triangular bracket cast into the pass. side manifold, but it's no biggie. Then you want to buy 2 1/2" head pipes for a 65. These will mate with the stock 2 1/2" system from the cross member back. You can also get the 65 FI spacer that eliminates the quick warm-up butterfly.

I think the manifolds and head pipes set me back around $350 total. Its a nice clean installation and breathes MUCH better than the 2 inchers. IMHO, this is the way to go if you have more than 300HP and don't want headers.

http://photos.yahoo.com/bc/chris_mau...iew=t&.hires=t


[Modified by 69L71, 10:19 AM 1/16/2002]

randy72

69l71,
Any pics. from up top, particularly of the pass. manifold?

69L71

I don't have any at the moment. I can take a few, but to be honest, there isn't much to show. It looks pretty stock from above, as it should. From the head to the crossmember its all stock '65 parts.

The clearance to the starter is a little tight becuase I have the 11 inch clutch, and thus a bigger flywheel and bellhousing. I don't think any mid-year small blocks had the 11 incher so the pipes don't bend around to clear for it. A mini-starter would certainly cure this but I've had no problems whatsoever with starter temp problems.

topless68

Sandersonheaders.com

63Banshee

I didn't see any cast iron manifolds on their Web site. If you get a chance could you point me in the right direction? Keep in mind that I'm only interested if they exit at the stock location.