[pressthatpedal]

I really love your thread! Great score, and rare too, less than 1300 made. Yours looks like I envisioned my 78 looking after being restored. I bought a 78 Solar Gold T/A, but without the Y88 package and T-tops, needing a total cosmetic restoration. Sadly, too many other Firebird projects and not enough room so I'm going to have to try and sell her without seeing her transformed to looking like yours.

[pressthatpedal]

Oh, and IMHO, I wouldn't change out the body side molding. The insert with the metal channels is much neater IMO, even if the insert starts looking a bit aged.

[Alvin]

Originally Posted by Alvin

Looking good & congrats again.

IMO & '78 T/A 6.6 W72 WS6 experience - note:

- the missing end link bushings were urethane from the factory for WS6. IIRC most ALL parts books will just show standard rubber end-link bushings which will work but without the urethanes the difference in handling is like night and day. A simple fix that dramatically increases suspension performance as designed by Herb Adams & Pontiac Engineering for WS6.

- the stamped subframe extension was installed as a heat shield for fuel lines from the OEM CatCon that was offset and positioned in the passenger footwell area.

- exhaust replacement is what you want it to be IMO. Personally both our T/A's have true dual w Dynomax Turbo style Muffs w factory Splitter tips. The '78 has a simple "H" pipe with factory manifolds...and ran 14:89 @ 95mph w closed shaker

Check out a 1978 PONTIAC SERVICE MANUAL Exhaust System

pages 6F-9 (Fig. 6F-12 F Series Exhaust Systems Chart),
pages 6F-10 (Fig. 6F-13 Exhaust Manifold Connections F-Series) (Fif. 6F-14 Converter Attachments F Series),
pages 6F-11 (Fig. 6F-16 Dual Exhaust System F Series),
Pages 6F-12 (Fig. 6F-17 Dual Tail Pipes Muffler and Attachments F Series Vin codes Z...)

- The factory installed manifold "EFE Valve" is usually long gone
- Note the 2-piece bracket hangers used to support the heavy OEM CatCon from the Trans crossmember, also usually tossed long ago
- Factory exhaust Muffs were "Turbo" short style

Interesting the factory manual lacks the illustration and documentation of the W72 Automatic Trans Only Dual Resonator exhaust...but that's not a concern for your 4-spd Y88.

Hope this info helps.

[Judge273]

Nice survivor car Bob! That will be a fun one to document and decipher.

Alvin cut back on the coffee....

[Alvin]

Originally Posted by Judge273

Nice survivor car Bob! That will be a fun one to document and decipher.

Alvin cut back on the coffee....

O-tay Buckwheat!

[Bentwheelbob]

Alvin - keep drinking the coffee. I appreciate your help.

Mike - thanks for the kind words. Underhood this one has more needs than the Sundance Kid.

Well, it took all of 15 hours in my possession before the car was rendered inoperable. The process has begun...Mission creep is on the horizon and I can taste it. Before My Pal Dave and I tore into it though we took the car on a 15 mile run and I've got to say I am really pleased. Despite the sway bar issue and 15 year old out of round tires, this car is tight. It also is surprisingly powerful and the engine runs very good despite needing some serious tuning, and despite there being a number of unplugged vacuum lines that are disconnected. In addition, the distributor cap was only half secured. This car will do fine once its had some attention. The foundation is great with no discernible issues. The interior is incredible, with the only nits being the gold gauge bezel and the sunvisors which have "floppy" vinyl on them. Everything works - clock, lighter and eight track included. Pretty damn awesome...

The carb, intake, heads and block are all the right numbers, and the block VIN checks out. While I thought that the intake and right head had mismatched paint, it is actually just the intake and valley pan. They are the right pieces, but they have been painted navy blue??? MPD and I are wondering based on the way this thing runs if at some point last century there may have been a cam swap. It is difficult to imagine why someone would have had the intake and valley pan out otherwise and they were clearly painted while off of the engine. The date codes on the heads are B098 and B038. The intake is L087.

I'm going to need a lot of help figuring this thing out and finding all the pieces. I appreciate all the help in the past, and all the help to come. I'll have some more focused posts coming that drill down on specific issues and questions. For now, here's a few pics.
The last two pictures show two vacuum points neither of which are hooked up. If anyone has any education to provide on these, please do so.

[2manyT/A'S]

I have about a dozen vacuum line detail pics I can email you....from a reasonably "unmolested" 78 W72......

Your temp/vac switch beside thermostat housing looks wrong....or the top is broke off.

[Alvin]

Thxs BentWheel

The ported vacuum switch on the front of the intake manifold should be bright blue...and here's some easy "tuning" info you may find interesting and has always "worked like a charm" on my T/A 6.6's:

[Bentwheelbob]

I'm trying to piece together the exhaust system and want to go with a 2.5" system. I've looked at the Dynomax mufflers and like them, but need help on either side of the muffler. I was going to get the Pypes system, but unless you get the X-Pipe system the muffler back tailpipe setup is not engineered for splitters. I don't really want to go with the X-pipe, so that would appear to rule Pypes out since the splitters are a must.

Questions:

1)If I can purchase from the Mufflers through the spiltters prebent from an online supplier, couldn't a local exhaust shop just bend the pipes from the manifolds to the muffler inlet.

2) Any recommendation on suppliers for the over axle pipes running from the muffler outlet to the splitters?

3) Same on splitters. Whose got the best pieces?

I appreciate any help.

Thanks,

Bob

[Alvin]

Originally Posted by Bentwheelbob

I'm trying to piece together the exhaust system and want to go with a 2.5" system. I've looked at the Dynomax mufflers and like them, but need help on either side of the muffler. I was going to get the Pypes system, but unless you get the X-Pipe system the muffler back tailpipe setup is not engineered for splitters. I don't really want to go with the X-pipe, so that would appear to rule Pypes out since the splitters are a must.

I'm certainly no expert, and many here can provide you more detailed info of current sources. Below are MOs. Hope it helps by giving you some ideas.

Questions:

1)If I can purchase from the Mufflers through the spiltters prebent from an online supplier, couldn't a local exhaust shop just bend the pipes from the manifolds to the muffler inlet.

Yes, since they won't be as original anyway - YPipe to CatCon - on 1978's. OR, you could source earlier 2nd Gen pipes for a 1974 manifolds to mufflers.

2) Any recommendation on suppliers for the over axle pipes running from the muffler outlet to the splitters?

Have you called PY and ask them with respect telling them you do not want an X-Pipe?
Check local GM dealer parts sources?
Gardner Exhaust?
Local exhaust shops...
I have old Year One Catalogs from the 90's that listed the OEM tailpipes & splitters...was same time they still sold factory sheet metal, etc.

Make sure you get them - tailpipes - with the tabs on the tailpipes that slide into the rubber lined hangers.

3) Same on splitters. Whose got the best pieces?

Splitters have been around for a long time from various sources, check the gauge of metal and the chrome plating.


I appreciate any help.

Thanks,

Bob

PS: sorry for the PM inbox full, I keep it that way got tired of PITA PMs from Dillion...

[Bentwheelbob]

I'm traveling again this week and want to get the exhaust ordered, but don't have the benefit of being home to check some details. Are the standard log manifolds on the W72 a two or three bolt flange?

[Alvin]

Originally Posted by Bentwheelbob

I'm traveling again this week and want to get the exhaust ordered, but don't have the benefit of being home to check some details. Are the standard log manifolds on the W72 a two or three bolt flange?

1978 Pontiac Service Manual shows manifold to exhaust pipe Fig. 6F-13 Exhaust Manifold Connections F Series Typical VIN Code Z:

L.H. Side 3 studs

R.H. Side 2 studs

[Bentwheelbob]

Originally Posted by 2manyT/A'S

Your temp/vac switch beside thermostat housing looks wrong....or the top is broke off.

So are the 1978 thermal vacuum switched made from the same unobtainium as the 1972 switches? Does anyone have a part number or better yet a used or NOS switch for sale?

Thx.

[J GLASGO]

Car is really cool! Love the 77 and 78 TA,s. I think the gold stick on moulding is definitely an improvement over the aluminum one. They look best without a moulding,but if you are going to have one ,the one that looks factory is the way to go! God knows these cars suffered from the parking lot wars back in the day! I have had several of these,and the first thing I do is call my dent guy to straighten the doors.

[roundportponchos]

Great car. Bob, nice

[Alvin]

From the “picture is worth 1,000 words” methodology: I scanned these Year 1 & Service Manual images for your use and information.

Note the tailpipe is for “Non-W72” as IIRC the TA also came with a “two-inlet two-outlet” single cross-flow transverse mounted muffler…so the Tail Pipe image below muffler connection is the incorrect bend for the W72 dual exhaust.*
It is included here for reference as to how the hanger (I previously called tab) and splitters were mfg’d and sold by GM & Pontiac.

For ease of use in the garage - Larger Full Size image links below:

- Tail Pipe HERE

- Fig. 6F-13 & Fig 6F-14 Converter & Exhaust Connections HERE

- Fig. 6F-16 Dual Exhaust System F Series HERE

*Refer to Fig. 6F-16 Dual Exhaust for the W72 Tail Pipes.

[Alvin]

Originally Posted by Bentwheelbob

So are the 1978 thermal vacuum switched made from the same unobtainium as the 1972 switches? Does anyone have a part number or better yet a used or NOS switch for sale?

Thx.

The “traffic signal” ported vacuum switch is referred to as the “EFE & EGR TVV” aka “TVV valve” in the “Street Tuning The Trans AM” information I had previously posted. There have been GM part #s and photos posted on PY in the past. At this time I do not have that information available. Perhaps Rocky Rotella, 2Many, etc. can provide that information?

Also a detail note: I noticed your gas cap appears to be an aftermarket part. No intention to nit-pick, wanted to provide you what the OEM style looks like. See #9864N in the illustration below for the correct gas cap.

[Alvin]

Originally Posted by Alvin

The “traffic signal” ported vacuum switch is referred to as the “EFE & EGR TVV” aka “TVV valve” in the “Street Tuning The Trans AM” information I had previously posted. There have been GM part #s and photos posted on PY in the past. At this time I do not have that information available. Perhaps Rocky Rotella, 2Many, etc. can provide that information?

Also a detail note: I noticed your gas cap appears to be an aftermarket part. No intention to nit-pick, wanted to provide you what the OEM style looks like. See #9864N in the illustration below for the correct gas cap.

Look closely here and you can see the "Bright Blue" TVV on this engine - back side of alternator - behind T-Stat housing:


Larger image of same photo link: http://2.bp.blogspot.com/-cKQ2b0_1i6...W72+engine.jpg

Blog hosting images above http://phscollectorcarworld.blogspot...codes-and.html

EDIT: Here's another large view of a TVV http://www.wallpaperup.com/uploads/w...d75274b76c.jpg

And a similar TVV on a 1977 Pontiac Can Am below

[Alvin]

One more for you Bob! A Beautiful restoration.
Note the lack of "insulation foam" to prevent "vapor lock" on the fuel pump to carb fuel line as used by Pontiac.



Image Article http://www.highperformancepontiac.co.../photo_07.html

[hada76]

alt wheel choice (if you want to spice it up a bit)