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I own a 1975 coupe that was built on October 23rd of 1974 and I am in the process of restoring the engine compartment back to stock.
My question is regarding the emissions (smog) pump setup on the 75 model year. I have the assembly and shop manual and they are giving me mixed signals as to how it was setup from the factory. Some say it has both A.I.R tubes on both manifolds and some say just the right side. I also found another page that says there is just one metal tube going straight into the Y-pipe on the passenger side. The smog pump bracket was left on the engine.
I have the EFE actuator ready to go but I need some clarity on the AIR pipe setup for my model year.
Any input is greatly appreciated! Thanks
This comes from the latest and newest edition of the NCRS 75-77 tech manual. We had some very original, low-mileage 75s to study, one of which was only 90 minutes from where I live...thus a visit to study and photograph it. It's hard to get a good photo to illustrate the single pipe but here's the description. The photo below is an overhead; you'll see the single hose on the passenger side that leads to the manifold pipe...no hose on the other side! The image also shows the various emission hose routings, including EFE. You should consider investing in a copy of the 75-77 tech manual...lots of photos!
Manifold Trees
In contrast to the typical manifold trees of previous years, the 1975-76 L48/L82 manifold tree is a single pipe that connects to the right-side exhaust pipe, below the exhaust manifold. Originals were gold cadmium but show a brownish finish that resulted from heat and aging, factors that contribute to the brownish appearance.
In 1977, A.I.R. reverts to the manifold tree of earlier years; a flattened butterfly-type reducer between the outer and center fittings. (Fig. Ch 4.11) The left side check valve and manifold tree point directly to an open space between the valve cover and alternator. (Fig. Ch 4.12 next page) Reproduction trees point toward the back of the alternator and stand nearly vertical. The right-side one is vertical, pointing upward from the exhaust manifold. (Fig. Ch 4.18) In 1977 only, these are plated black cadmium or black zinc of varying shades. (Fig. Ch 4.11).
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1975 L48 TH400 Smog Pump Setup
