Quote:
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.