Part Two: The Topside
Our rotating assembly places the pistons 0.002 inch below the 10.190-inch-tall deck. Note that although the dish takes up most of the piston face, sizable reliefs still needed to be cut into the face for the valves. The photo on the right was taken during the mock-up phase of the build, so you'll notice that the top of the piston doesn't have the thermal barrier coating applied yet.
1. At the time of this build, ARP didn't have the right length head studs in stock, so we were forced to order +0.250-inch longer parts and then turn them down in a lathe. | 
2. Cometic multi-layer steel head gaskets were employed and measure 0.040 in thickness with a 4.600 bore. | 
3. We chose Manley titanium valves and retainers to make the valvetrain as light and reliable as possible. The intake valves measure 2.450 inches in diameter and have 5/16-inch stems, and the exhaust valves are 1.80 inches in diameter with 11/32-inch stems.
The valvesprings are LSM's 700A 1.670-inch od units, minus the inner spring. The cam profile is designed around this particular rate, and by removing the inner spring, it all works out. Pressure at the seat is 310 pounds, and the open pressure is 835 pounds. |
4a. Because we have more than 300 pounds of seat pressure, we chose the 0.250-inch-wide beam J2K Mohawk rocker arms, which are the strongest rockers Jesel offers. The J2K's design is further strengthened with tool steel lash adjusters and extra-wide 0.250-inch needle-nose rollers. Our rocker arm ratio is 1.7:1. Our block wasn't machined for lifter bushings, so we opted for Jesel's tie bar-style lifters. The oil circuit in these lifters sends pressurized oil to the roller, bearings, pushrods, and upper valvetrain. Another benefit of these lifters is that they are available with offset pushrod cups to aid in moving the pushrods away from the intake runners in heads like ours. | 
4b. Mocking up the rocker arms and supplied stands revealed that we'd have to machine the bottom of the stands to get the geometry perfect, so that the roller swept across the tip of the valve properly. | 
5. Once the mockup phase was complete, we ordered pushrods from Manton. Our pushrods for the intake taper from 7/16-inch to 3/8-inch with a 0.168-inch wall thickness. Our exhaust pushrods taper from 1/2-inch to 7/6-inch with a 0.188-inch wall thickness. Perhaps the coolest aspect of Manton's pushrods is the quick turnaround time. We ordered our custom pushrods, and they were delivered two days later. |
6. Pro Filer's Hitman single-plane intake manifold was designed in conjunction with the pros at Reher Morrison Racing Engines. Features include a 1-inch-tall spacer cast into the manifold, a one-piece design, and spread ports that align beautifully with Pro Filer's 12-degree heads. | 
7. We also had MBE port-match the intake, massage the transition from the plenum to the runners, and equalize the runners as close as possible without going to the expense of filling and epoxy work. | 
8. After installing the intake manifold, we turned our attention to the oil pump drive unit. Dave coated the shaft seals and bronze gear with assembly lube, and after determining that the cam gear was meshing nicely with the drive gear, he applied silicone sealant to the slip collar of the drive unit to prevent any future oil leakage. |
9a. Topping off the manifold is a Quick Fuel Technology P-4512 1,250-cfm three-circuit carburetor. | 
9b. Like any good custom carb, Quick Fuel built this one specifically for this engine, but it also features items that are standard on most of the company's carbs, such as lightweight aluminum fuel bowls, notched floats, and jet extensions on the secondary side. The extensions prevent the jets from becoming uncovered during hard launches, ensuring that fuel is always on tap during holeshots. The metering blocks are precisely machined from billet aluminum to prevent warping and leaking down the road. | 
9c. This carb also features annular boosters, polished venturi surfaces, Teflon-coated throttle shafts, and stainless steel throttle plates and hardware. Before the carb was bolted to the manifold, we slid-in a combination phenolic spacer to isolate the base of the carb from the hot manifold. |