1975-1979 Corvette Exhaust System Installation

Posted January 29, 2013 by Zip Corvette in Corvette Technical Articles

If you have a 1975 to 1979 Corvette and you want to pass most emission inspections, you are going to need the correct exhaust system, one that installs easily and, most of all, fits. You don’t want to have to hold your tongue just right to make it align, then use some very colorful language and a big hammer to complete the installation. The answer to this problem is Zip Corvette Parts, 8067 Fast Lane, Mechanicsville, VA 23111, (800) 962-9632. They offer a complete 1975 to 1979 Corvette exhaust system with the correct Y-Pipe, catalytic converter, mufflers and hangers. The best part about the whole system is that it fits. It is an aluminized system which I personally recommend. The aluminized system will outlast any carbon steel system and it seals better than most stainless steel systems, not to mention the price savings.

The 1978 Corvette needed a complete new exhaust system so we went back to an original stock exhaust. The hardest thing about the whole installation was removing the old exhaust system.

It is now time for a catalytic conversion.

Click on the images for expanded views – it’s much easier on the eyes. 

Step 1

01: This is the entire Corvette exhaust system we received from Zip Corvette:  The Front Y-Pipe, Inlet Pipe, Catalytic Converter, Rear Y-Pipe, Right and Left Stock Mufflers, Mounting Hardware, Clamps, Brackets and a Heat Riser.  A shop manual and assembly manual, both available from Zip Corvette, will also be very useful.

Step 2

02: Place the Corvette securely on jack stands.  Start by removing the entire old exhaust system.  If the old system has been on a long time, you will probably need a hacksaw, chisel and sometimes a torch to totally remove the system.  Sometimes a big hammer will even help!

Step 3

03: Lay out the new exhaust system to get an idea how it fits together.  Pre-fit all of the pipes.  You may have to take a file and clean the edges so that the pipes slide freely into each other.  This will make the installation much easier.

Step 4

04: Whenever you install a new system also install a new heat riser valve.  This will ensure you of an exhaust system that operates correctly.

Step 5

05:  Install the heat riser and donut on the front Y-Pipe and loosely mount it into place.  It is also a good idea to use new exhaust studs and brass nuts on each exhaust manifold.  This will also help to make the installation so much easier.  This will also be helpful if you have to remove the front pipe at some later date.  The brass nuts will not seize to the exhaust stud as a common steel or cadmium nut will.

Step 6

06: Slide the inlet pipe through the hole in the frame and onto the front Y-Pipe.  Do not clamp it.

Step 7

07: Align the catalytic converter with the flange on the inlet pipe and start to bolt it into place.  By leaving the inlet pipe loose, you can move it around so that you can bolt the converter into place.  When the catalytic converter is bolted to the inlet pipe, slide it back onto the front Y-Pipe.

Step 8

08: Mount the new rear Y-Pipe exhaust hanger onto the body.  Bolt the rear Y-Pipe onto the catalytic converter and attach the rear hanger bracket around the pipe.  Leave it loose for now.  You just want this much of the exhaust system to hang in place.

Step 9

09: Make sure the rear suspension heat shield is in place.  This helps to keep the exhaust heat away from the rear end suspension and differential.  If you do not have one, check with Zip.  They should be able to help.

Step 10

10: Install the new muffler hanger rubber blocks on each side of the frame.  The tab slides into a slot in the frame and the bolt holds the bracket in place.

Step 11

11: Slip the Corvette muffler over the rear Y-Pipe.  Use a muffler clamp to hold the J-Bracket in place and slide the J-Bracket up into the rubber muffler hanger block.

Step 12

12: Install all the muffler clamps onto the pipe.  Make sure that none of the threaded ends of the muffler clamps hang down.  Either turn them up or to the side.  By doing this you will make sure that you have ground clearance and also the threads are less likely to be damaged which makes removal at a later date much easier.  Slowly working from the front to the rear, align each pipe.  The pipes cannot touch any part of the frame, floor pan or body.  If they do, you will have a noise or pronounced vibration.  The assembly manual for your year Corvette has numerous exhaust system diagrams with the correct clearance measurement for the entire system.  Use the manual as a reference.  As you get a final alignment on each pipe, tighten its clamp securely.  These clamps must be tight to make a good seal.

Step 13

13: The tailpipes should hang down at the same level on each side.  Nothing is worse than seeing one pipe lower than the other.  You may have to compromise by moving one up and one down to achieve the same level, but it will look better.

Step 14

14: You also want to make sure that you have clearance between the rear Y-Pipe, the suspension and the ground.  If the pipe is too high, it will rub against the suspension.  Too low, it will hit the ground.  After everything is checked and tightened, start the car up and check for exhaust leaks.  If it all checks out, set the car back on the ground.  You now have the solution to the catalytic conversion.
1975-1979 Corvette Exhaust System Installation: Corvette Exhaust Install

Source: Zip Corvette Parts
8067 Fast Lane | Mechanicsville, VA 23111 | (800) 962-9632

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