Posted by Matt Wilson [172.69.70.50] on Saturday, October 20, 2018 at 11:26:58 :
In Reply to: Dual carb intake/split exhaust headers posted by Mike [162.158.74.60] on Thursday, October 18, 2018 at 22:25:25 :
Mike, there are quite a few posts on this subject on the www.p15-d24.com website, if you search their archives. The website is all about Chrysler/Dodge/Plymouth/DeSoto flathead-powered cars and trucks, although not too many Power Wagons.
Anyway, most of the posts don't give hard numbers regarding dump gains with a dual-carb setup and headers, but most of them say it DOES make a noticeable difference, even without a cam upgrade. There are a couple of folks who say it doesn't make any difference in power, and that people who claim it does are just being fooled by the nice exhaust sound. But as I said, the overall consensus seems to be that it does make a significant difference. The hard numbers I've seen seem to indicate something like 20 - 25%.
As for pricing, of course, it depends on what condition they are in. I saw a factory dual intake and dual exhaust setup that looked rather rough, and the guy (on eBay) was asking over $900. I don't know what he actually got for them, though. Of course, that was for factory equipment, which is rare. I bought an aftermarket aluminum dual truck intake made by a company called Nicson (pronounced Nixon, I suppose?), in like-new condition, for somewhere around $400 (don't remember the exact number). I also bought very nice brand-new cast iron headers from Tom Langdon, and I think they were around $300. You can look at his website for his current pricing. I'm pretty sure he has them for the 23" engine (such as the 230) and the 25" engine, such as the 251 or 265). The stuff I bought is for a 265 flathead that I'm building for my '49 Power Wagon. I also remember talking to one salvage yard that had a dual intake, and I think their asking price was $300 or $350. Based on photos they sent me, it looked to be in good shape (I don't recall now why I didn't go with that one). There are guys (such as George Asche and others you can find on p15-d24) who will take your existing intake and exhaust manifolds and turn them into duals for a couple hundred dollars for each manifold, give or take. Then there is Offenhauser, who I believe still makes new dual-carb intake manifolds for the 23" flathead, and last I heard, they were selling for around $200. Some flathead performance enthusiasts say they are not that great on performance - not as good as other brands. So that gives you an idea of the range of prices. Some more pricing info can probably be found on the p15-d24 forum posts, if you look in the forum archives.
Good luck!
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