Because of its all around performance, we stuck with the ZZ4 hydraulic roller camshaft. With a 112-degree lobe separation and 0.474-inch intake lift and 0.510-inch exhaust lift, the ZZ4 cam offers a smooth idle, great power curve, and will work with stock length small-block valves.
Before installation, the cam is wiped down with mineral spirits, dried, then engine assembly lube applied to all the lobes. The assembly lube will protect the lobes of the cam during initial startup until oil pressure builds and fully circulates oil through the engine.
To make installing the cam easier, screw a couple of long bolts into the nose of the cam so you have something to grip and keep the cam lobes from getting nicked while inserting the cam into the block.
For this engine we used factory roller lifters with the factory spider retainer. Since roller lifters don't need to rotate like flat tappet lifters, they have to have a retainer of some sort to keep them from spinning because of the rotation of the cam. Most factory setups use a stamped steel spider to hold down tabs over each pair of lifters that keeps them from spinning. Most aftermarket lifters use a crossbar design that has a linking bar between the lifters, eliminating the need for a spider retainer.
Here you can see the 'dog bone' retainers that keep the lifters from rotating in their bores. The arm of the spider has a tab the rests on the center of the dog bone to keep it in place while the lifters are operating. Since 1987, all GM small-blocks have been roller blocks, meaning theyre cast with taller lifter bores than earlier Gen I blocks to handle the tall factory-style roller lifters and they have the three holes in the center of the lifter valley to retainer the spider. Even though the Gen I Chevy truck engines didnt get factory roller cams until 1996, they used roller blocks with the tall lifter bores, so retrofitting/upgrading them with a roller cam is easy.
Before slipping each lifter into its bore, give it a coating of engine assembly lube, including the tips. Use engine assembly lube and not oil; the assembly lube's thicker viscosity will keep the oil from running off the parts before you start the engine for the first time.
With all the lifters in place, the spider retainer is set down in the valley, with the tabs lined up on the lifter retainers.
It's a good precaution to use some thread locker on the three bolts to hold the spider in place, so engine vibration doesn't loosen them up and cause the valvetrain to go crazy and eat the motor. Tighten all three bolts down, and the lifter retainers and spider are secure.
Because the ZZ4 cam has an LT1-style nose, we had to use an LT1-style timing chain. We opted for GMPP's single roller chain, which has more than enough strength to handle what we'll be doing with this engine.