[AzMike]

I am building a 389 from a 63 Catalina to replace the 326 originally in my 63 Lemans convertible.

I want to have a true dual exhaust made for this and I want it to start with a set of headers. I'm assuming the 389 block will not change what headers would fit on a 326. Does anyone know of headers that clear on a 63?

[tom s]

A lot depends on where you set the engine in the car if a front mounted trans.I had them custom made on mine as I moved my engine a couple inches toward the pass side to give more room around the steering and clutch linkage.Tom

[AzMike]

As of right now I was just planning on installing it just as the 326 came out. That was part of the appeal of the 389. I didn't have to change anything.

Am I wrong there?


BTW. My car is still original with the 2 speed auto transmission/ transaxle.

[tom s]

Is the 389 crank drilled and tapped for the rope shaft?Tom

[tom s]

Also remember the little 7in R&P wont take much abuse with any kind of sticky tires.The auto trans is pretty tough but not the R&P.A stick shift would not like a 389.Ask me how i know!Tom

[AzMike]

I used the crank out of the 326 when I built the 389.

[Chiefkey]

That's what I'm planning to do with mine. Did you have the engine re-balanced for use with the 326 crank ? Was there much of a weight difference between the two cranks and the reciprocating mass ?
JK

[tom s]

It SHOULD be rebalanced for sure.Not much diff in the crank weight but pistons would be heavier.With a stick shift setup you would not have to use the 326 crank.Tom

[AzMike]

Originally Posted by tom s

It SHOULD be rebalanced for sure.Not much diff in the crank weight but pistons would be heavier.With a stick shift setup you would not have to use the 326 crank.Tom

It was balanced. I'm not personally building the engine so I can't tell you how much difference there is between the 2 rotating masses. However, my engine guy came HIGHLY recommend in pontiac circles.

Again I'm running a stock but completely rebuilt 2 speed auto transmission.

[Chiefkey]

Tom S. , we need to get you to write a book or otherwise put together a detailed compilation of your knowledge re: the 61-63 Tempest/Lemans drivetrains. You're a wealth of info on these strange little "creatures". Would love to read more on the Super Duty versions too ! As for the original question regarding headers, I picked up a set of Hedman "shorty" tubes with the idea of saving some weight, and although I haven't weighed them yet, they sure don't feel any lighter than the original cast iron exhaust manifolds !
JK

[tom s]

As I remember the pass side worked but I think there was a issue on the drivers side.I bought a set once and sent them back.There are guys on here that have come up with a header that fits.I put a set of first gen long branch years ago and had to cut a big notch on the drivers side of the X member.I only remember it was not worth the labor involved.The best besides custom was a set of original 421 SD tempest factory headers.They would only work with a ropeshaft setup.They would not clear a front mount bell.Tom

[beemergary]

I have 1968 Hooker GTO on my 63 and 61 421's. The front sway bar has to come off.

[JohnFromVentura]

The front sway bar has to come 0ff to get them on or for good?

Originally Posted by beemergary

I have 1968 Hooker GTO on my 63 and 61 421's. The front sway bar has to come off.

[AzMike]

Originally Posted by JohnFromVentura

The front sway bar has to come 0ff to get them on or for good?

So, I'm looking for hooker headers for a 68 gto?

[tom s]

The one that goes behind the engine crossmember?I took that off when I had my 2 in custom headers were built.Tom

[Doug]

Since you are using the 2-spd automatic, I assume you are keeping the rest of the ropeshaft drivetrain. Therefore, you will not have all the clutter of clutch linkage, etc.

Accordingly, as Tom mentioned, the drivetrain will not survive much thrashing by the more powerful 389 engine. That leads me to question the necessity of an expensive set of "performance" exhaust headers when whatever setup an original 326 dual exhaust system consisted of should be more than adequate.

I don't know exactly how the original 1963 326 dual exhaust setup was accomplished. For the 1963 Tempest 326, Hollanders lists a #541626L left side manifold and a #545466R right side manifold. (The #545466R was used on most all Pontiac and Tempest V8's in 63 and 64 including the 63 4cyl.) Hollanders list a #9773442L for 64 Tempest V8's and lists a #545470L for 63-64 Pontiac V8's. Hollander DID NOT list a different left side exhaust manifold for a DUAL exhaust 1963 326 car.

Of course the 63 326 #541626 L left side manifold was a one-of-a kind setup in that it exited toward the front of the engine. It appears that any 63-64 Pontiac V8 or 64 Tempest driver side exhaust manifold could be used on a 63 326 to direct exhaust towards the rear to facilitate a dual exhaust pipe.

It could be that the original 1963 326 dual exhaust system used the front-exiting #541626L left side manifold and front-of-engine crossover pipe and then redirected the left side exhaust back to the driver side with a crossover to the driver side after the engine to make the dual pipe. Since the dual exhaust was part of the 1963 326HO engine package which was available in both manual and automatic cars, it is unclear how they could have accommodated a rear-exit left side manifold with the clutch linkage cars.

It might be possible to use a #545470L rear exiting manifold and a flex pipe stainless steel exhaust tube elbow connector joint to make a left side manifold setup for a dual setup.

I seem to recall that the old 3-tube "Blackjack" headers for early GTO's would fit nicely in a V8 63 Tempest. I don't know if those type headers are available now but back in the day they were quite inexpensive. (If you check them out and would be interested in some, I have a buddy that has a new set of them he bought several years ago for a 64 GTO.)

Good luck.

[tom s]

IMHO,headers have no place on a everyday type driver car.My 455 in my 69 bird has long branch.Tom

[gavin]

The 68 to 72 cast GTO manifolds fit I think. Not as good as headers but better than stock. If the 389 is a good going engine it may be worthwhile making a small adaptor plate to fit the 389 crank to the shaft. You also need a spacer for the flex plate to the crank as the 336 used the later flex plate flange mount diameter. If you have to rebuild the 389 use the 336 crank. If you want a adaptor drawing to suit the 389 crank I can give you one.

[gavin]

On my 63 the drivers side is using a rear facing manifold. I think this fine on automatic cars but as doug said may not work on stick shift.

[Doug]

Gavin, it appears he used the right crank in building the engine (see post #6 above).

I 'm glad to hear that a rear facing manifold was used originally. I had never known how they did the dual setup. I guess the question remains on how they did a dual setup on a stick shift car.

Do you have any numbers on your driver side manifold that may correlate with any other regular Pontiac manifold number?

Thanks for the info!