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Header Advice - Any experience with these?


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Find out more about the heat coating. Ceramic is best but high temp paint could also be called 'heat coated' so don't be disappointed when it all peels off in 3 months. Ceramic reduces under hood temps, one of many problems associated with running a header and they will last at least twice as long (with ceramic) if looked after.



Fit is always a problem. Never heard of anyone putting a header on and not having to put several dings in it to clear the steering box or... something. Find out the policy of adjusting it to fit.


The other fit problem is the head gasket. The lower studs use a large cone washer to bridge across the intake and the exhaust flanges. The intake flange is something like 1/2" maybe 3/8". Headers usually use something much thinner and clamping them down is a problem due to the different thicknesses and they can warp or be warped from the welding. Check that it is flat and have it milled if not... depends on the quality.


I assume you have a U-67 head? The W-58 has round exhaust ports. The square will work on U-67 ... round is better for the W-58.


If you have the U-67 head the stock intake and exhaust will be bolted together. The bottom of the intake will need sealing and check the header clearance under it. Also you will now have no warmed intake and it may will (Seattle) run rougher in cold weather. Now this may be a summer car so this may not matter.



Troll insight. That's about $100 per horse power gained on a street L20B.

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Here is another option ,, if your thinking of spending serious coin anyway,, have someone do this for you.





nice coated exhaust mani






Man i had to wade through 20 pages of Skibbers 710 build to find it again..






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Are you saying that I'll gain about 2 horsepower by running a header on an otherwise stock L20B exhaust set up? That makes the purchase seem more about looks, and possibly sorta stoopid (trolling myself).


On a stock L20B 3-5hp maybe and at 5,800 RPMs (much less lower down) A header shouldn't even be considered unless you NEED (not want) more breathing room for your engine. A 'big' cam, multiple carbs (or a single larger) ported head, larger valves or basically things that will promote a good breathing head, that is being held back by the exhaust.


The stock exhaust is far and away more than enough for a stock engine.  It's only when you start moving more air that you will need it.... and then you will get way more than 3-5 horsepower from it!!!






fits perfectly every time, no leaks doesn't come loose.

rusts but never rusts out for the life of the car and three others.


runs cooler under hood

probably already on your car (510) so nothing to instal.

maintenance free.

makes good power on an L20B. These were used in 510 racing at ultra high RPMs. A lot or money and research went into these. I call them the 'cast iron header'



(none of the above but...) lighter

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Hey, I'm extremely biased. I bought a header for my L16 521 truck back in the '70s. Cost about $80 back then. It didn't fit right, had to remove a torsion bar to get it on. Took all Sat and most of Sun to swap it. Once running it was no faster or better and for that I wasted two days had to live with...


$80 less

It came loose at the collector every 2-3 months.

was rusty as hell in 2

loud enough that you got sick of it if you drove it more than a half hour. Less if you were hung over or otherwise not feeling well.

hot under the hood

cut off my perfect down pipe.


If it wasn't so much bloody work I would have put the original manifold back on but by then I had discarded it... big mistake.


$300 dollars??? Spend it on something more deserving which is just about anything else other than a header.

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I have a lot of experience with TopEnd headers, un-coated ones will last me about 5 years before they start leaking, and where they leak is in the middle of the 4 tubes, not sure if a coating will make a difference there, generally I just cut the header off where the 4 tubes come together, fix the leak, and then weld it back together, that gets me a few more years, I believe I have went threw about 3 or 4 of these headers over the last 20 years.

I would do what Nana suggested and get a stock L16 exhaust manifold and mod the outlet for a larger pipe, after all it is an L16 exhaust manifold, there might be an L20b manifold out there also like the one that Nana posted a photo of, I don't see them very often.

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Yeah, between what you are saying and what I saw on the link Bananahamuck posted, I am convinced that staying with the stock mani is the way to go. I may spring for the ceramic coating, but I've got a few months before I'm ready for this decision, anyway.


Besides, this whip is kicking my wallet's ass and needs to be smacked back down.

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This 4 into two style manifold was only used on the L16 and L18 engines. (you do not need to ceramic coat these as their half life from rust out is about 1,375 years)



The L20Bs made through '77 were different with a 4 into one pipe that was co-joined to the bottom of the intake to warm it.  A heat riser valve would direct hot exhaust under the intake to help evaporate the fuel when cold. The valve used a metal coil that relaxed when hot and  closed. Naturally they would rust and get old and failed in the open position and warmed it when they were hot also. Not the best set up. The '78 and up used coolant in the head through the runners of the intakes just like the L16/18 used to do. The '78 and up intakes are separate from the exhaust.


'77 L20B


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What all these guys said is true, and trust me I went the ceramic coated way and these headers are not worth it. Fitment wise no problem witht he newer ones on the market now in the engine bay,but to fit right witht the intake manifold you got to grind down the flange for a more flush fit when maiting up to each other with the bottom studs and the big thick washers to hold them together, And like Mike said no gains that would be feil at all. Get a stock one and i believe some were there useing the square port manifold that flows well, Grind it down smooth it out if you wish and ceramic coat that and it will look good and last for ever..

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Go with the L16 manifold and build a long tube 2-1 head pipe with the collector behind the transmission mount.


I bought this set-up from a buddy and put it on my hillclimb car. The work on the factory manifold and the exhaust pipe was done at Rebello's shop. It was on a 2.3L L series engine used in my buddy's rally car.


They "up-graded" his rally car to a 4-1 header. Midrange power was actually higher with the manifold/long tube headpipe. The 4-1 header only helped at top end and then by only a few HP. In the long run my buddy wasn't sure the change was worth it.

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