I have an Offy 4-bbl manifold and Holley 390 vacuum secondary. Should the carb be mounted with the primaries towards the front of the engine or facing the engine? I've seen pictures of both ways. Also, does the manifold need to be modified with the little air dam in front of the rear runners like Chrysler used to show in their Direct Connection manuals? Thanks...

cheers,
Ken

I have mine mounted with the primaries parallel and closest to the drivers side fender. I think the fuel distribution is better and Im a little faster with it mounted that way. However I am not consistent enough to prove it.
Just my 05 worth,
Frank
I also have the Dams in this manifold.

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

My primaries are toward the left side, stock Offy manifold without dams, no distribution problems.

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Joshua

mine is mounted primaries face front of truck/ no problem...no dams in manifold either


keep n roddin'

As long as it's right side up, it doesn't seem to matter.

CJ

Primary on mine to the front, in case your doing this statistically.

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Part of Tyrde-Browne Racing

600 Edelbrock on a Clifford facing front, just cause linkage hook-up didn't need modifying. Some say carb. spacers work here so fuel can vaporize more before it hits the runners.

mATHEMATICALLY IT evens out runner length doing it sideways. You will need to mod the adapter plate to do it.

I want to put a divider in there too. I am a ways off from doing the 4bbl conversion. Luckily mine is a manual tranny!

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick