OEM Header? 4-2-1

[Guest nateoneel]

I found this at the junk yard today for $35. It looks like a factory header 4-2-1. Has no smog ports and has fins on it. The only problem is this has square ports like on a U67 and I have a W58 with round ports. Can I use it? Or should I trade someone on ratsun for a shorty round port header? 78' 620

Thanks for your advice,

nate

[Bugeye]

that looks like a stock manifold

[Guest nateoneel]

well that why I wrote OEM header. Isn't it?

[bagged_datsun]

it should be fine, just don't go square head to round header it will leak

[Guest nateoneel]

so it is an upgrade from my OEM exhaust mani I have on now?

[motavated]

You took that off a 620? If so I'll take the bottom part of your hands....

[Guest nateoneel]

yeah it came off a green 77 620 in lagrande OR. I really want to use it or trade it for the right shorty header for my 620.

[ggzilla]

Yes, these are good performing, some say as well as an aftermarket tubular header but never rust out. If it matches the ports on the head.

[Guest nateoneel]

thats just it, I have round ports (W58) and this is a square port mani. I understand it won't leak.

[motavated]

Supposedly bagged datsun said it will leak...

[datsunaholic]

Square port manifold on a roundport head isn't optimal, but it won't leak as long as you use the squareport gasket and haven't hogged the ports out. And don't run it hard. The other way around is trouble.

[banzai510(hainz)]

did the studs break off on that manifold?????

 

I do have a short round port header. But wont gareentee it

[Bandit240]

Ive got the same thing on the L18 that came out of my 74 parts truck. Was going to use it until i spotted that it has square ports.

[Guest nateoneel]

did the studs break off on that manifold?????

 

I do have a short round port header. But wont gareentee it

 

 

There are no studs in it. Just treaded holes. If you have a shorty round port header can you post pics of it on here? And Are you willing to trade???

nate

Edited January 9, 2009 by nateoneel

[racerx]

How are you going to use it if your ports are different:rolleyes:, maybe you can bring it back.

[datzenmike]

Ive got the same thing on the L18 that came out of my 74 parts truck. Was going to use it until i spotted that it has square ports.

 

It's not from the '77 for sure. It looks very like the '74 L18 manifold but doesn't have the EGR tube and I don't see the threaded hole for it either. Another thing is the missing air injection holes... I think this may be from an earlier L16 motor m

aybe a 521?

 

OEM header...:D

[Bandit240]

Ok, so it isnt like what ive got.

 

[SHADY280]

either way your gonna need a gasket, so buy one and check how it fits, if it doesnt show light thru or close to an edge, your fine. square to round is def. a no go. round head to square header i feel will work fine

[athoose]

Ive got the same thing on the L18 that came out of my 74 parts truck. Was going to use it until i spotted that it has square ports.

 

Do you have a good collector/downpipe? Not cracked or riddled with rust. PM me if you want to sell.

[athoose]

Ouch, never mind.

[Edz280zx]

For what it's worth..my Z has round ports on the head and I'm using a square port header...no problems with leaking so far..it's been on there for a year or so.

[datzenmike]

Ok, so it isnt like what ive got.

 

 

 

 

Probably L18 manifold. This is from a '74 w/L18:

 

http://i138.photobucket.com/albums/q251/datzenmike/L%20Z%20Heads%20and%20Motors/enginepossibleL18620exhaust.jpg[/img]"]

[Guest nateoneel]

I unbolted it from a U67 head. Does that mean its from an L18 or L16?

[72240z]

Yes, these are good performing, some say as well as an aftermarket tubular header but never rust out. If it matches the ports on the head.

 

Who ever says that is incorrect. Stock mani is never going perform as well as a equal length tubi. Stock cast def would take way longer to rust out and also isn't prone to cracking though for sure.

[72240z]

Square port with round header leaks because the corners don't seal. Where as round port with square header seals fine its just not port matched which is ideal.

 

Blocking off the corners of a square header by using them on a round port head hurts flow enough to negate the point for using it, esp if your going to just just another cast stocker. It's a cool stocker and the bottom half is nifty but better you just use the correct piece.