Are Z24 2WD and 4WD headers the same?

[Jitenshakun]

I see two part numbers from Pacesetter but the pictures look like the "4WD" one has some emissions piping whereas the "2WD" one doesn't. 

 

https://www.summitracing.com/parts/psm-70-1112/make/nissan/model/720/year/1983

 

https://www.summitracing.com/parts/psm-70-1113/make/nissan/model/720/year/1983

 

I'm swapping to as part of welding in an AFR bung and deleting emissions tubes. I'm not doing it for mega power or amazing sound. I'll also get them ceramic coated and avoid header wrap. 

[datzenmike]

They also have to clear the torsion bars and 2wd and 4wd torsion bars and frames are slightly different.

 

The 720s uses an air injection system (AIS) that takes advantage of the vacuum pulse directly behind every exhaust pulse. A small pipe from the exhaust manifold runs up the the air filter where there is a one way reed valve that opens under vacuum, sucking little pulses of oxygen rich filtered air down into the exhaust stream. The catalytic converter need oxygen to 'burn' the emissions. I have noticed that 2wd trucks have one and 4x4s have two of these pipes.

 

In addition both 2wd and 4wd exhaust manifolds have a sheet metal skirt and a pipe to the air filter snorkel. This pipes warmed air to the automatic temperature control (ATC) the mixes warmed and cooler outside air and regulates it to a constant 100F. The engine runs more predictably in all weather and carburetor icing is eliminated.

 

Get whatever is appropriate for your truck.

[Jitenshakun]

 

 

I've eliminated all the emissions as my truck is an engine swap with butchery to the emissions all over. 

 

I'm going to get the plugged 2WD setup and have my muffler shop bend or swap out pipes as necessary. 

[datzenmike]

What I was saying is if you have 2wd get 2wd header. I think they are subtly different.

[Jitenshakun]

Subtly different on the fit at the head or out to the tail pipe? So long as I can bolt it to the head my muffler shop can handle the rest. I hope... 

 

The heads should be the same Z24 to Z24. 

[datzenmike]

1 hour ago, datzenmike said:

They also have to clear the torsion bars and 2wd and 4wd torsion bars and frames are slightly different.

 

 

 

Get whatever is appropriate for your truck.

 

The header has to pass down and miss the torsion bars and the frame. The muffler shop can't fix that. Get what fits your truck. No sense putting a 2wd header on a 4x4 if it might not fit. The very fact pacesetter offers a 2 and 4 wheel drive header should mean something.

[Jitenshakun]

Sigh. That is wisest. 

 

Why is the 4WD one so ugly.