Chevy Big Block Zex Nitrous Perimeter Plate Install - The Big Squeeze

What does it take to add an extra 311 hp? We simply unbolted and removed the carburetor from the carb base. Then using the supplied gaskets, we sandwiched in the Zex perimeter plate. Longer carburetor studs were also installed into the manifold. Next, we bolted the carburetor back on top.

Our carburetor of choice was the Holley 1050 Ultra Dominator. While they may seem a bit pricey, our justification relies on proof that they are ready to go, right out of the box every time. These newly redesigned models have a reinforced casing for added strength, metering system for greater fuel flow, and all-new surfaces have been machined to improve their appearance and gasket sealing. The 1050 also includes a progressive mechanical throttle linkage, dual 50cc accelerator pumps, four-corner idle systems, and annular boosters.

Precision-machined jets are used for adjusting both nitrous and fuel flow. They feature a special internal taper to minimize turbulence resulting in very consistent flow and power. Zex offers jets at $3.50 each.

1. GM Gen VI big-block with a 4-bolt main measured in at a 4.310-inch bore and a 9.800-inch deck height.
2. Milodon baffled oil pan (PN 30955) features an 81/2-inch deep sump to hold 7 quarts of oil.
3. Our Comp Cams pushrods (PN 7906-8/7757-8) came with a 3/8-inch cup and measured in at 8.580/9.470 intake/exhaust.
4. For spark, an MSD pro-billet distributor (PN 85561) was set at 36 degrees for the base dyno pull. Expelling the fumes were a set of 21/4-inch Hedman headers with 36-inch primaries, 4-inch collectors and 18-inch extensions.

The Zex perimeter plate kit includes both a nitrous and fuel solenoid. They install and flank either side of the carburetor. In our case, we used a custom Westech Performance bracket to mount our solenoids.

The Pro Nitrous solenoid (PN NS6642) comes with a 1/4-inch NPT inlet and 1/8-inch outlet and only draws 16.7 amps. The Pro Fuel solenoid (PN NS6641) features a 1/4-inch NPT inlet and 1/8-inch outlet. It only requires 1.8 amps of draw.

Proper bottle pressure is a must. Zex suggests bottle pressure between 900 and 1,000 psi for optimum performance. To create that pressure, forgo the dangerous torches and use a bottle heater (PN 82006).

Zex suggests installing spark plugs that are at least two steps colder. Due to the increased power created from nitrous, the heat generated in the combustion chamber goes up and also increases the possibility of detonation. As a general rule of thumb, always listen to the manufacturer's recommendations to ensure safe operation.

Base Run

	TQ	HP	A/F Ratio
AVG	616	602	12.8
MAX	663	789	13

Nitrous Run - Jets 82/72
Base Run

	TQ	HP	A/F Ratio
AVG	695	699	12.3
MAX	939	1,091	13.4