Re: [Amc-list] Header for Concord Wagon 6cyl?

[Frank Swygert <farna@xxxxxxx>]

I think that for the money it's a waste of time, unless you do find a used one that isn't rusted out or beat all up. You'll get a modest increase in power by going to a generic turbo muffler and a 2"-2.25" single exhaust and opening up the air filter housing. Probably 10-15 hp between the two. I doubt headers would give you more than 5 h over the above. I don't see any advantage to duals over singles on an engine this size. The only difference is almost double the cost for duals and a bit different sound. Unless you like the engine real loud, stay away from baffle type mufflers (Dyno-Max Super, FlowMasters, etc.). The generic turbo mufflers offer a straighter exhaust path once pressure builds, are reasonably quiet for normal driving. They also have a thin fiberglass wrap around the outside (inside the shell though) that muffles vibration through the shell. 

You have to be careful on the air cleaner though! If you plan on driving in cold weather the car will be harder to crank if you go with a completely open air filter. One trick is to get a spare housing and add a second snorkel to it, or take a larger snorkel from a salvage yard housing and modify the Hornet housing for it. 

Before I bought a new header, I'd get a 91-95 4.0L head and exhaust manifold from a salvage yard and have the head rebuilt. If there are pull-your-own-part type yards around you should be able to get everything for the cost of a new $300 header. There's still not going to be a big jump in power, assuming you use the carb and intake (you'll need the mid 80+ aluminum intake not bolted to the exhaust Mark mentioned -- find one off a Jeep CJ or through 89 Wrangler if no cars in the yard, or ask about one here, Craigslist, or e-bay). I did the swap and only got a small increase in power, maybe 5-10 hp (already had the exhaust and air intake mods). The distributor on the 83 engine I have needs recurving bad! I have a 390 cfm 4V carb too. Of course part of the problem is the 100K+ mile 258 short block, with about 10K on it in low range as a snow plow! 

-------------
" From: Richard Estermyer <javelinman74@xxxxxxxxxxx>
" 
" Any suggestions to where to get a header for the 258 in my 1980
" Concord wagon?  Would I notice a difference as I did in the 360 Mat
" wagon? (25% inc).  Advantage over single or split header?  Anyone
" have a lead for one?

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)

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