Help me select a header-L20b

[KamakSun]

Hey all

I'm about to put dual 45dcoe's on my l20b, but first I need to bolt on headers. Please let me know what would be best to run; the manifold currently on, the short header or the long one. The exhaust is completely rotted so it will be replaced most likely with 2 inch pipe and a muffler of all y'alls recommendation(I'm hoping for something that would have been used on the car in the late seventies or early eighties. Below are pictures of what I have.

 

Thank you,

Kamaksun

 

 

 

 

[wayno]

Keep what you have on it, it's a stock header itself and if you were to look at it close you would realize it, what you already have is the best out there.

[KamakSun]

Is it stock to the l20b?

[datsunfreak]

Is it stock to the l20b?

 

No, stock to the 510. 

 

The L20b exhaust manifolds are junk. The stock 510 manifold is a very nice piece. 

[datsunfreak]

FYI, if this is a 510 header, it will hit the floor with an L20b. 

 

[KoHeartsGPA]

Yup, take that mani out, clean her up real good, slap on new gasket and you're set, that's the best way to go.

[tr8er]

The headers are prone to rust through, and they tend to lead at the block Union. They offer little in flow gain (if any, not sure). You have plenty of flow stock. I believe your head flow is your weak link. But those dual 45's will be nice

[Dolomite]

Old hot rodders trick learned from the keeper; take a wire wheel to that stock manifold and get the surface rust off, then rub anti sieze into it, re-install and fire it up and let it idle till it quits smoking. Now take it for a blast, romp it pretty hard, leave the windows up as it may smoke again. It forms a nice matte grey coating that lasts better than paint if done correctly.

[datzenmike]

The cast exhaust you have is most likely from an L16 although the L18 also uses a similar one. It is used on 510s but not 510 specific. It was also used on the L16s used on the '70-'72 521 and the '73 620.

 

I have one on my L20B and have no problems with it.

 

 

The only advantage to the header on the left is it is lighter. Otherwise it...

 

Rarely fits well, doesn't clear steering or suspension. The stock manifold is a perfect fit

Comes loose needs tightening at flange.

Rusts out, rarely lasts 4-5 years. The stock manifold lasts forever.

Noisy.

Expensive. The stock manifold is free.

Bitch to install. The stock manifold is already there.

[KamakSun]

Thanks all!

 

What muffler should I go with? Les at classic datsun set me up with a used dynomax but I'm hoping to keep the car true to its early eighties rally roots.

 

Happy Sunday,

 

Kamaksun

[KamakSun]

I will be going the anti seize "paint" route. I'm pretty confident that I've put anti seize on every bolt, even the ones that should have loctite

[datzenmike]

Try for the largest muffler you can fit. If going to 2" pipe add 2.25" adapters and run a 2.25" inlet muffler. A 'turbo' style is ok with lots of dampening material inside. Don't go fart can... isn't necessary isn't worth, it sounds like shit. 

 

Don't go to 3" pipe either. just 1.75 or maybe 2" is more than enough. This keeps the exhaust gas speed up which helps to limit mid range torque loss from a too large pipe.

 

A 'nice' muffler and new pipe will get you more than a header will. Headers are useful if you have major head work (larger valves/cam porting) more compression and multiple side draft carbs but it really is hard to beat the stock manifold.

[banzai510(hainz)]

ceramic coat it.

[scooter]

I have the dynomax stainless muffler on my car and it sounds great, good throat and not crackly like a flowmaster or cherrybomb or rice pipe.

 

If the motor has stock guts use the manifold but if it's mods you may see more top end from the long tube.

[KamakSun]

I went with a crimped not welded turbo style muffler

[Stoffregen Motorsports]

Did you end up doing the "anti-seize paint"? That shit will kill you if you breathe it while it's burning in.

[KamakSun]

Nope, I had it ceramic coated.

 

I'll post a pic when I roll out of bed.