Though high-profile camshafts, aluminum cylinder heads and larger carburetors get most of the V-8 upgrade attention in car magazines, the distributor is the most important piece of equipment under the hood. Your engine literally does not go without it. Many older classic cars came with OEM breaker-point distributors that were inefficient and often left drivers stranded by the side of the road. MSD has been at the forefront of high-quality aftermarket distributors, and installing one of its distributors into a V-8 is straightforward and requires only a few basic tools.
Disconnect the battery.
Set the engine so that the number one cylinder (front driver side) is at top-dead center. You can do this manually by using a breaker bar on the crankshaft in front of the harmonic dampener to turn the engine. Remove the spark plug from that cylinder and place your hand over the spark plug hole. When you feel a puff of air come through the hole as you turn the engine, the cylinder is at top-dead center.
Remove the vacuum hose that runs to the vacuum advance "bell" on the front lip of the old distributor. If the hose is in good condition, set it aside for re-installation. If not, discard it and use new hose to replace it. Loosen and remove the bracket that holds the distributor in place on the intake manifold. Disconnect all eight spark plug wires from the old distributor, then remove the coil wire from the distributor and the coil.
Disconnect the coil from the firewall with a screwdriver and remove it. Remove the distributor cap, and make sure that the rotor is pointing to the number one cylinder. If it is, slide the distributor up and out of the engine.
Fit the MSD wiring clips and harness to the wiring that had been hooked to the coil. This will plug directly into the HEI system of the MSD distributor.
Remove the cap from the MSD distributor and align it with the hole in the intake manifold. Turn the bottom of the distributor shaft (which spins the rotor) so that the rotor is pointing to the number one cylinder. Slide the distributor shaft in through the hole on the intake manifold and replace the distributor cap. Connect the modified coil wires to the HEI box on the driver side of the MSD distributor, then replace the spark plug wires. Replace the distributor bracket, but do not tighten it down until after you have timed the engine. Reattach the vacuum hose to the vacuum advance port on the distributor. Turn the ignition on, and time the engine with the timing light.
