Interesting performance from an OEM 4V Intake

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Q1SVT

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A Boss 351C like build, but a 383 ci  @7000 RPM

First runs with a Holley Strip Dominator Manifold HP 625 at 7300 Torque at 5600 490
Factory Dual Plane with .500 divider cut down HP 585 at 7000 Torque at 5100 470 

https://www.facebook.com/ken.maisano/posts/3224929100891150

Ford generally did not CUT the dividers, they used cutout
spacers... Many 351C owners got the 780 carb & spacer from the 1969-70 Boss/Eliminator 302.  [see pic]

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mjlan

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That's the aluminum, Boss 351-only intake right?

 

Q1SVT

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That's the aluminum, Boss 351-only intake right?
Yes, it is a Boss D1ZA-CA intake...   But ALL 1970-73 Ford 351C OEM 4V intakes are the same castings [runners].  The differences are iron - aluminum, and the size of the spread bore... yes even the 'L' intake is a spread bore, the primaries are smaller than the secondaries.

Maisano modified the D1ZA-CA spread to a square bore 850 carb w/ 1-3/4" bores, removed the area between the primary -secondary [increased the intake plenum area, needed for a 383ci+], cut the divider 1/2" allowing the motor to balance the two planes, and allow it to act more like a single plane intake @ 7,000+ RPM.    

Kind of raises questions on the BS tests of the OEM Ford intakes.... 

A 351C ci that will run idle to 6,000+ does better w/ a four hole intake [w/correct bore sized to carb] and a 1/4"- 3/8" cutout or spacer...  depending of how much you spend @ 6,000+

jm2c

 
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c9zx

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Those are really great numbers with factory heads and 383 CID. Chuck

 
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