Poly 318 Intake Manifolds

(Applicable to 277, 301, 303, 313, 318, 326, 390, 402 engines)

Factory Intakes

1822004 – Factory iron dual-plane 2 x 4 barrel “Dual Fury V-800”:

• The best iron factory performance intake manifold originally offered on 1957 – 1958 “Dual Fury V-800” packages. Excellent balance of performance and streetability when paired with proper carburetors, camshaft, etc. For all-out race, the Weiand WPD4D will outperform this intake.

1619826, 1859229, 1828103 – Factory iron dual-plane 4 barrel “V800 Super-Pak”:

• Known as the Super-Pak option on 1957 – 1959 engines.
• Produced from 1956 – 1962.
• Excellent street/strip intake for performance throughout the rpm range. Superior to the Weiand 7503 for street use.

1859228 – Factory iron dual-plane 2 barrel (1956 -1966):

• Excellent torque and throttle response for street use. Equipped with a Trans Dapt 2040 adapter and a Holley 7448 or 80350 (350cfm) or 4412S (500cfm), the intake will outperform a four-barrel for street use. To take advantage of the 500 cfm carburetor, the two-barrel plenum opening needs to be enlarged. (4-barrel carb on the two-barrel intake upgrade advice credit Gary Pavlovich).
  • Note: 1963 – 1966 engines were all 2-barrels.
  • Note: All trucks came standard with two-barrels.

E5793M – Factory “Chrysler Sea V” iron marine intake, dual carburetors.

2735919 – Factory aluminum dual-plane 2×4 barrel (extremely rare):

• Offered in 1956 through Plymouth dealerships as a performance part. The best factory performance intake manifold in design and weight. Excellent balance of performance and streetability. For all-out race, the Weiand WPD4D will outperform this intake.

Aftermarket Intakes

Weiand 7503 – Single-plane 4 barrel

• Ideal for an engine that will spend most of its time above 3,500 rpm prepped with a performance cam, headers, high-stall converter, and gearing of 3.55:1 or lower. Will benefit greatly from head porting. Usable on the street, but the throttle response and torque will suffer at lower rpms.
• When used on a stock engine, low-rpm performance will suffer.

Weiand WDPSQ – Early single-plane 4 barrel:

• Ideal for an engine that will spend most of its time above 3,500 rpm prepped with a performance cam, headers, high-stall converter, and gearing of 3.55:1 or lower. Will benefit greatly from head porting. Usable on the street, but the throttle response and torque will suffer at lower rpms.
• When used on a stock engine, low-rpm performance will suffer.

Weiand WPD4D – Single-plane 2 x 4 barrel:

• The most high-performance mass-produced intake for an A-block. Ideal on an engine that will spend most of its time above 3,500 rpm prepped with a performance cam of at least around 264/.450”, headers, high-stall converter, and gearing of 3.73:1 or lower. Will benefit greatly from head porting. Usable on the street, but the throttle response and torque will suffer at lower rpms.
• When used on a stock engine, low-rpm performance will suffer.

Weiand WPD3D – Single-plane 3 x 2 barrel:

• A rarer intake designed for small-base four-bolt Rochester, Carter, and Holley. As a single-plane design, it suffers from similar low-rpm limits as the other Weiand intakes but shares the same high-performance capabilities above 3,500 rpm. The dual-plane Edelbrock P600 is a superior intake for streetability. The photo below shows the manifold with spacers installed.

Edelbrock P600 – Dual-plane 3 x 2 barrel:

• Most were designed for early 3-bolt Stromberg 97 and Holley 94 carburetors, but they made a rare four-bolt version for small-base Rochester, Carter, and Holley. 3-bolt to 4-bolt adapters are available, however. The best available 3 x 2 intake for a street A-block.

“Wind Tunnel” dual-plane intake:

A rare limited-production aftermarket dual plane high-rise A-block intake manifold designed by foundry owner Javier Vasquez and engine builder Gary Pavlovich. Sold from approximately 2014-2019 when production ended when Javier and Gary left the project.

• Strong HP & TQ gains over factory and the Weiand 7503 when equipped with the proper carburetor, cam, and other components. 
• Warning: Be extremely wary of anyone requesting money for supposedly pre-ordering this intake since as of 2023 the intake is not in production and no evidence exists it will ever be produced again. I have received multiple emails from different people since 2020 explaining that they paid over $500 USD for a supposed pre-order to collect enough orders/money to run a batch who then never received an intake or refund.

Justin’s Cross Ram Intake

While I am not the first to bolt Offenhauser 5497 cross-ram adapters onto a poly Dual Fury V800 intake, I will lay claim to designing and fabricating a cable and bell crank throttle linkage system and using unsilenced Mopar “Charger 225” air cleaners (see the finished system). While I have not measured the difference myself yet, multiple dyno results out there show a gain of 10% – 16% HP on small block Chevys and Fords, and the ported heads, larger valves, and 6,500 rpm camshaft on my Poly 390 stroker should make good use of the this induction.

Hinkle LS1 Retrofit 

• GM LS1 intake runners line up extremely closely with the A-block’s, and Buck and Clark Hinkle retrofitted an LS1 Victor Jr. single-plane manifold on their A426 build. Note that the Hinkle engine was built for the sole purpose of pulling dyno runs in a competition, evident in the valley pan that appears to have limited perimeter fasteners and is glued in place. To make the intake work long-term on a street car, one would need to machine adapter spacers for the intake (see photos below), build a valley pan, and build a coolant crossover with thermostat. One could break up a valley pan that is captured by the intake manifold adapters, much like a factory metal B-block valley pan/intake gasket. A race-type detached coolant crossover might be an option. While not for the weak-willed, after all this work one would have many LS1 intakes to choose from, including the dual-plane Edelbrock.