Hilborn Part *PDC-4 Cam Cover Drive For Small Block Chevrolet Engines

1. Loosen oil pan & remove stock timing chain cover, gasket, the three (3) sprocket bolts.
2. Bolt on the hex drive spud using the allen cap screws supplied.
3. Adjust the cover-to-spud clearance by means of the .015” and .030” shim washers supplied. With the timing chain cover gasket off, place the washers on the spud, .015” at a time, until the cover is raised just clear of the engine block. Remove one (1) .015” washer. Install the new cover gasket, which will give proper running clearance. Failure to set the clearance properly can result in damage to the drive and pump!

IMPORTANT! Be sure to remove the HILBORN pump before attempting to remove the harmonic balancer. Failure to do so will result in a broken casting.

Hilborn Part *PDC-6 Timing Belt Drive For Small Block Chevrolet Engines

1. Bore the crank pulley to 1.250” to accept the crank spud.
2. If using a water pump, use a single-groove crank pulley.

Hilborn Part *PDC-7 Timing Belt Drive For Big Block Chevrolet Engines:

1. Pump mounts on the RIGHT side of the engine looking forward.
2. A single-groove crank pulley should be used and bored out to 2.250” to accept the crank spud.

Hilborn Part *PDC-8 Cam Cover Drive For Big Block 396”-427” Chevrolet Engines

1. Loosen oil pan & remove stock timing chain cover, gasket, the three (3) sprocket bolts & sprocket. The timing sprocket hub must be reamed to .875” to receive the register on the drive spud. Replace sprocket.
2. Bolt on the hex drive spud using the allen cap screws supplied.
3. Adjust the cover-to-spud clearance by means of the .015” and .030” shim washers supplied. With the timing chain cover gasket off, place the washers on the spud, .015” at a time, until the cover is raised just clear of the engine block. Remove one (1) .015” washer.

Install the new cover gasket, which will give proper running clearance. Failure to set the clearance properly can result in damage to the drive and pump!

IMPORTANT! Be sure to remove the HILBORN pump before attempting to remove the harmonic balancer. Failure to do so will result in a broken casting.