I am in the process of restoring my 1967 lemans which has the 326 engine. My question is it worth replacing the exhaust manifold with headers. I have looked at other threads on this website and it looks like there can be problems with the full length headers so i am now considering either the shorty version header or HO ram air (if that will work). Any advice would be greatly appreciated.
Headers, I mean long tube headers, are good if you're willing to make the trade. That trade is that you'll be getting the best possible exhaust performance-wise in exchange for some significant headaches in installation, maintenance, fitment, and longevity. It doesn't matter what brand --- they *all* have these problems in various degrees. The significant differences are in performance. Sadly, what's best for performance is usually worse for the other problems - that's just the way it is. I'm running headers on my car, and I just deal with the issues. I had to relocate some of the brake system components, alter the backdrive linkage (steering column lock), and when it's time to rebuild the passenger side lower control arm the header on that side is going to have to come out in order to get to the bolts.
If you're willing to take a small step down in performance in exchange for almost none of the other problems, then nothing beats a *good* set of repro Ram Air manifolds.
Unless there's some difference in pre-67 heads that I don't know about (I'm mostly a later --- 350/400/428/455 --- guy), they should bolt right up. The vendor who makes probably the best quality repro parts, Ram Air Restorations, would know the answer.
I wouldn't bother with shorties. You'd be going through some of the pain of 'real' headers without getting the benefit.
Thanks for the info. I was leaning torwards the Ram Air manifold just to avoid any complications. I see different companys that make these. Is there one that you could reccommend.
On another question i have is in regards to my transmission. I am the second owner of this car and have owned for about 1 year. I decided to do a complete frame off which to my surprise has been fun but a lot of work. The engine was completely rebuilt about 12000 miles back and the only changes made was adding a 4 barrel quadrajet carb and intake manifold. The transmission is a 2 speed automatic powerglide and i am considering replacing it with either a 3 or 4 speed automatic. Not sure exactly what i have for rear end gears but suspect they around 272 gear ratio and need to know if i change the tranny should the rear end also be modified.
Thanks again for your advice.
I like the ones from Ram Air Restorations. I don'r run their manifolds but I do have some of their other parts, and have found them to be top quality.
If that's the factory 2-speed, it's not a Powerglide. It's a Pontiac Super Turbine 300 - a different tranny. There are some parts that are common with Powerglide, but that's about it. Changing the trans isn't a reason to change the rear end, by itself. High gear is still high gear, regardless of how many changes it took to get there. Pick the rear axle ratio based on how you're going to use the car - i.e. street, highway cruising, race, etc.
My 2 cents, based on experience with a few 326 cars: go with the cast iron HO manifolds. No leaks, no issues, they just plain work. Your rear gear is probably a 2.78, which is a standard LeMans/Tempest ratio. A TH350 trans would be a straight bolt in deal, cheap and effective, and it's 2.75:1 first gear ratio compared to your current 1.78 ratio will make the car feel like it has 150 more horsepower. So, leave the rear end alone, and bolt on a set of cast HO manifolds and install a TH350. That's what I'd do. You'll end up with a car that runs very strong off the line and in town, and also be a 20mpg cruiser on the highway. Changing the trans will literally transform the car.
If the engine is relatively stock then go with the manifolds. My old 326 had ported heads bigger cam and rpm intake so the headers would compliment all the other components of the engine to make it breathe better. But also had fit meant issues, had to carve a little piece of the driver side lower control arm out and went through about 3sets of gaskets before there was no more leaks
As stated in the other responses go with factory style. I have hooker long tube headers that I will replace with the oversized ram air III exhaust manifold. Besides the headers leaking they are a pain when dealing with the linkage for my transmission and changing oil filter. I think the heat from them caused my starter to fail and well as making wiring to the starter difficult.
I not sure if it is worth ceramic coating, I have never had ceramic coated exhaust system. I understand it can reduce temp by up to 40%
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I agree, headers are a PITA and only add a few HP. I have a 350 in my lemans, 3.36 gear, turbo 350, headers, cam, intake and carb. It runs OK, but the real fix to wake it up is cubic inches, I had a 400 in it that ran better, now have a 455 ready for it. Personally, I would keep it as a cruiser with the 326, and think bigger motor for the future, then rear gear. Tranny would be a great swap. With the gear and all in mine, I lost any real gas mileage and don't have the performance to match the mileage.
Thanks for all the info. I have decided to go with the ram air III exhaust manifold. Not sure but Can I use the ram air manifold on a 400 or 455 engine? If thats the case then then i won't mind spending the money for them.
On another note I gotta admit it's been a lot more fun reassembling this car then tearing it down. The current status of the car is i have the body off the frame, sandblasted the frame and coated it with por 15, replaced all the bushings,shocks, ball joints, air lifts on the back side (kept the original control arms) and added disk brakes front and back. I want to get the engine back on the frame so i can move on the the body. I was lucky enough to find someone locally who has a rotisserie that is willing to let me borrow it. Only problem is he has gone south for the winter so i am on my own as far mounting the body to it. My lemans is a convertible so i have welded and bolted bars across the door openings for support. Any advice or tips would be appreciated.
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