3.2 Header Size

[North Coast Cab]

I'm finding conflicting information on the best header size for a 3.2. Basically stock other than the exhaust and chip.

Does anyone know the size of SSI's or '74 and earlier HE's?

1 1/2, 1 5/8 or 1 3/4?

Race car application.

TIA, John

[Jeff]

For track applications on a 3.2 you should use 1 3/4 headers.

Got the strut brace. Thanks.

[Bill Verburg]

SSI primaries are 35mm(1 3/8")ID, for street use you would want ~42mm(1 1/2")ID, for a full race motor ~44.5mm(1 3/4") ID

[pmajka]

Does SSI have a website, i would like to know how Much 1 3/4s heat exchangers would cost????

Sold by our host. I think they have specs.

[pmajka]

Yes, but looking for more specs. maybe some photos.

[gumba]

According to Richard at PMO the header size is based on whether your using a muffler or straight pipes. On my 3.4 race motor using 50mm PMO's he suggested a 1 5/8" with a muffler and a 1 3/4 - 1 7/8" with straight pipes.
You should consider using the 993 heat exchangers instead of the SSI's, if you want heat in the race car. Tyson has a post discussing the advantages.

[JeremyD]

Primary tube size
SSI 38mm OD/ 35mm ID
GHL 41mm OD/ 38mm ID
B&B 41mm OD/ 38mm ID (small tube)
B&B (964 version) 44.5mm OD /41mm ID (large tube) too big for a street 3.2
SC/RS 42mm ID

[pmajka]

Ah, this is useful!

for those who dont know, I have an Andial 3.7L motor.
I think ( but am not sure) i have stock 3.2 exhaust? (just a little pinch)
So, i was looking at either BB 964 or 993 HEs.

But dont the 993s have the exhaust studs rotated 90degrees?

Was the stock Carrera 3.2 and the stock 964 exhaust the same?

[JeremyD]

Originally posted by pmajka
Ah, this is useful!

for those who dont know, I have an Andial 3.7L motor.
I think ( but am not sure) i have stock 3.2 exhaust? (just a little pinch)
So, i was looking at either BB 964 or 993 HEs.

But dont the 993s have the exhaust studs rotated 90degrees?

Was the stock Carrera 3.2 and the stock 964 exhaust the same?

Yes, the 993 HE - if you want to use on either a 964 or 3.2/3.4/3.7 need to have the flanges rotated on one side of the engine.

I am actually thinking of selling my 964 B & B heat exchangers and MK muffler -

[pmajka]

Hmmmm....contact me offline.
pmajka AT shiraz.dynip.com

[84Euro]

JermyD, I sent you a PM

[sus911]

here's what Ben (M&K) is doing for me.
993 HE's flipped, 2/1 s/s muffler:

[JeremyD]

Here are the 964 B & B headers