Poncho Swap whooos!

[smallblockwagon]

Im swapping from a 355 to a 455 with edl round port heads...

I cant find headers :x any help would be great.
I have called every major company with no luck. I can have a custom
set built for about 2k but thats a little much for me.

Thanks

Eric

 

[84GP455]

First of all CONGRATULATIONS!!! that is an awesome upgrade and you won't be dissapointed with the 455!! If i were you i would forget about headers and i would use a set of Ram Air II or ram air IV(the first round port heads from the Pontiac Division.) stock exhaust manifolds. They should be easy enough to find and they will give you as much horsepower as regular tube headers but without the headache of having to change the gasket every year or so. I have a set of stock 455 manifolds on my 455 and i haven't had to change the gaskets on them in over 10 years!! Try that with regular headers.....the gaskets are metal, not asbestos so they last longer plus they won't bottom out and get crushed like regular tube headers.

GOOD LUCK!


Ram Air III
The Ram Air III is a 400 cubic inch engine with a milder camshaft than the Ram Air II and D port heads.


[edit] Ram Air IV
The Ram Air IV is a resurrection of the Ram Air II.

 

[KrisW]

I would think a 455 can use the same headers as a 400, no?

There are G-body pontiac headers available. What size are you trying to find?

Oh, and I don't have gasket problems when running B-O-P headers. You have to cut the flanges through the bolt holes to look like (I) for lack of better description. I typically cut the holes between the exhaust ports and leave the middle/top and outer holes alone. When you cut the flange it allows the different port flanges to heat up and cool down separately which normally warps the solid flange (unless it is super heavy, like 3/8" plate!) and blows the gaskets out.

 

[shotgun]

Repro Ram Air manifolds or custom are your only option.

IA,who made headers for these cars,went nuts up.Something about 2 brothers going in different directions. 🙁

Never tried "long Branch" style in a Gbody. We had a 4100# firebird running in the mid 12z so they cant be that bad.

Just did ram air manifolds on a 79 TA,it's so nice just to bolt'em and forget'em.

What are the specs on the motor?

 

[Vern]

www.remflex.com

 

[KrisW]

They sure are pretty!

I bet with enough phone calls, SOMEONE still will make you a set for less than a fortune!

http://www.wallaceracing.com/headerpics.htm

 

[megaladon6]

i have the earls pressure master gaskets which are similar to the remflex. i haven't had to retorque them at all and they seal great! i don't see them on summit for an olds application but that doesn't mean much.

 

[84GP455]

yes all Pontiac v8's are interchaneable so the 400 is the same as the 455 as far as parts go mostly....ok.... so they make a gasket that's supposedly leak proof,,,ok so what about making tube headers that are hassle free, installs easy, and don't need tweaking to line up with the bolt holes. Also what about rusting???what about bottoming out on the exhaust flange every time you go over a speed bump because headers are so low to the ground??? As far as Pontiacs go there aren't many tube headers available out there, plus there isn't much room on the drivers side near the steering column, it's a tight fit
I am just merely stating that for the extra 15 or so horsepower they aren't worth it....... to me it is easier to install factory exhaust manifolds and forget about them!! The ram air manifolds flow just as well as tube headers,,,,they tested this theory in Pontiac High performance magazine!

 

[KrisW]

When you say that ram air manifolds flow as well as headers, what headers were compared with them? 1 3/4" or 1 7/8" primary tube? Long tubes, I guess?

The reason I'm asking is because you said that 15 hp is not worth it to you. Do they flow as well or are they 15 hp behind? I'd like to know because if they are similar on engines between 400-500 flywheel hp then I would run those manifolds as well.

Can you port or extrude hone the manifolds and increase power potential or does that ruin the flow charachteristics? I see that repro ram air manifolds are about the same price as new headers over at Jim Butler so my gears are really turning here.

 

[bigdan]

back in the late 70's I had a ram air 4 400 with the famous headers look alike manifolds....
switch to LT headers and went on dyno : gained 7 hp but lots of troubles too leaking gaskets , scrubbing ....2 months later put back the manifolds for peace of mind ....