STEP 2- ADAPTING AND TRANSFERRING ORIGINAL PARTS TO THE EDELBROCK MANIFOLD
While the Edelbrock setup has most of the original bosses for brackets and accessories, there are a few things that require fabrication or adaptation from the original intake manifold to the Edelbrock manifold. Of course, all the sensors, vacuum connectors, thermostat housing and thermostat, EGR valve, heater-hose connections and lifter-valley shield need to be removed from the original manifold and installed on the Edelbrock manifold. The stock oil-fill tube can be knocked out of the original manifold by placing a large socket in the top of the tube and tapping the tube back and forth with a soft-face hammer.
Just about everything fits in the stock location on the new manifold, but there are a few exceptions. Here are some of the things that needed adapting or fabrication:
Coil Bracket- My original coil bracket needed to be clearanced to fit on the original mounting boss, due to interference with the high-rise runners of the Edelbrock manifold.
Lifter-Valley Heat-Shield- You will need to grind the heads off the rivets that attach this shield to the underside of the factory manifold, and attach it to the bottom of the Edelbrock manifold with the rivets they provide. I needed to re-bend a significant portion of the original shield to match it to the contours of the replacement manifold. It is easily-formed sheet steel, but it took a few tries to get the holes to line up to the holes on the bottom of the Edelbrock manifold once the shield has been stretched and reshaped to fit. I also used some red Locktite to ensure those rivets didn't come loose.
PCV Valve- 1979 and newer factory intake-manifolds used a threaded fitting with a curved tube and an S-shaped hose to connect the PCV-valve to the port on the rear of the carburetor. The Edelbrock intake only has the 1" hole of the older 1978 and earlier AMC V-8 engines. You will need a grommet to install a 3/4" PCV-valve into a 1" hole, then a length of 3/8" rubber fuel-hose (provided with the Edelbrock intake manfold) to connect to the port on the back of the Edelbrock carburetor. The hose that Edelbrock supplies has a slight curve to it, which is sufficient for making the bend in this hose without kinking it.
Fuel Line- The Performer carburetor has its fuel-inlet on the rear of the passenger-side of the carburetor (the brass fitting in the upper left-hand corner of the picture below), whereas the fuel-line exits the fuel-filter at the front of the driver's-side of the intake manifold.
Rather than risk a fire from a chafed or melted rubber hose routed around the carburetor, I bent a length of 3/8" steel fuel-line to connect to a banjo-fitting (necessary to clear the factory air-filter housing), and adapted the 3/8" line to the factory fuel-filter's 5/16" outlet with a Purolator fuel-pressure regulator using different-sized fittings for its inlet and outlet.
I also used a thermal sleeve (not shown in the above picture) over the fuel-line to prevent the fuel from percolating in the lines when the engine is hot, and I used a small angle-bracket to mount an insulated 3/8" line clamp to keep the fuel-line from vibrating and moving around.
The trick was to bend the line so that it didn't rest on any hot engine parts, obstruct the vacuum ports or emissions-equipment, and so that it didn't block the adjustment of the idle mixture screw. This required a few tried with some different tubing-benders to get it just right.
As you can see, it takes a rather convoluted piece of tubing to snake through all the lines and fittings without touching anything, but with everything installed it doesn't interfere with anything, and the idle-mixture screw can be adjusted with the air-cleaner on. So far there havn't been any hard starts from vapor lock due to fuel boiling in the line.
Throttle-Cable Bracket- The Performer carburetor is wider than the stock 2150 carburetor, so the bosses mounted in the factory locations on the Edelbrock intake put the factory throttle-cable bracket too far over and back to work with the Edelbrock carburetor. The stock 2-bbl throttle-cable can be used with the 4-bbl using a supplied throttle-ball stud, and Edelbrock sells an adapter to relocated the throttle-cable bracket to the proper position. I opted to fabricate my own bracket using a piece of aluminum stock bolted to the top of the original. It so happens that the original throttle-cable bracket had an extra hole which sits right over one of the mounting bosses when the bracket is in the proper position.
To bridge the gap for the other hole, I cut a trapezoidal piece of aluminum, drilled the three holes to match the three existing holes in the factory bracket, positioned the bracket to enable proper throttle-cable movement, and drilled the fourth hole to match the other mounting-boss on the intake manifold.
The location of that fourth hole turned out to be tricky to get just right, as it was the critical determining factor for adjusting throttle-cable travel. If it was too far forward, the throttle-cable would not have enough travel for achieving wide-open throttle, and if it was too far back, the cable would be holding the throttle open at all times. To get the proper positioning, I measured the distance from the bracket to the throttle ball stud on the original intake and carburetor (about 5 3/4"). I positioned the new adapter to obtain the same distance, then marked and drilled the hole.
The only other modification to the bracket that I needed to make was a bit of grinding on the side of the brackets to clear the vacuum-fitting that is located in a different position on the Edelbrock manifold than on the factory manifold.
On to Step 3: Installing the New Manifold