[68GoatHO]

Anyone help with correct exhaust manifolds for the WS engine with 16 heads. I have been looking, found a set on the parts place. Need advice and questions answered before I purchase. Any help is appreciated.

[John V.]

The '68 WS used the D port 16 Heads.

The HO exhaust manifolds were as follows:

Left side was new for '68 and has the casting p/n 9791637.

The RIght side was carried over from '67 and the casting p/n is 9777642.

It was assembled with a Heat Riser Valve. The Service Replacement included the HRV and the assembly was p/n 9777641. You will never find this p/n on the casting itself, only the 9777642.

A lot of references get confused buy this. Anybody familiar with Engineering Drawings will understand that the Assembly was made up of a group of parts, one of which was the manifold casting, in this case 9777642. We refer to the Assembly as a "higher level" part which required a unique p/n. PMD did not service the bare RH casting so you will not find p/n 9777642 in the Master Parts Catalog.

In April '68 PMD announced the elimination of the trouble prone HRV. However the Dealer Service Information Bulletin No. 68-I-56 announcing the change noted that the GTO and Firebird 400 HO engines were among the exceptions to the HRV elimination.

This might have been because they had not yet released a Right side HO manifold without the HRV. PMD did release a new HO Right side D port manifold for '69 without the HRV, with a new p/n of course.

[68GoatHO]

Do you think the part numbers below from the parts place will work!

1968 Pontiac GTO/LeMans/Tempest RAM AIR H/O EXHAUST MANIFOLDS D-PORT WITH 2-1/4" OUTLET (9791637 LH 2 BOLT FLANGE & 9797072 RH 3 BOLT FLANGE) - PR

EX 11239F
Ex5351G

[68GoatHO]

John V.
I have more questions, would you be able to provide more detail on other concerns?

[Singleton]

You will get more responses if you post the question in the "68-69 GTO Tempest & Lemans Tech" section

[John V.]

Agree with Singleton.

The exhaust manifold p/ns listed by The Parts Place appear to be correct for the '69 D port HO application. The RH manifold lacks the HRV that the '68 RH manifold included so it should work although won't be exactly "correct".

The Parts Place offers the 9777642 RH manifold for the '67 application but I am not sure it includes the HRV. Even if it does, they only sell as a set and don't seem to list it as a set matched to the 9791637 LH manifold.

Kinda just depends on how close to original factory correct you'd like. Since they are repros, they will not look exactly as originals even if the p/ns are accurate.

I'm not a '68 expert, the guys on the '68/'69 forum will be more knowledgeable.