Whats the best cfm aluminium intake manifold that will fit under a w25 hood and oai air cleaner on a 455 F block? For those of you out there that have the oai setup, what intake manifold and distributor are you using?

 

Only the facotry W-25 intake fits without mods.

To run an aftermarket intake you will need to get creative by milling the carb plenumn & use a drop air cleaner base plus cut down the OA! seal.

 

I guess I should of said, what will fit with mods? For those of you out there with the w25 option, what intake manifold are you running?

 

The Edelbrock Performer I understand will work with minimal mods.

 

On a big block the Performer is a good bit taller than stock so I think it will need some effing with.

 

I've read on at least one Olds site that the "relic" Edelbrock O4B will work with the W-25 hood.

 

I have used the edelbrock o4b for years under my w25 hood with zero mods, and used any distributor I wanted including HEI, stock, Accel, mallory, msd and I have had all of them over the years. The o4b with a little intake matching and grinding off 3/4 of an inch of the center plenum divider will run up to 6000+ rpm and pull strong! I grind off the edelbrock carefully and blast the intake and then paint it and nobody can tell its not a factory intake, you can find them at swap meets for 150 or less. People forget about them but they work!

 

good info guys, what about the edelbrock torker or victor with modifications?

 

Have you seen a Victor?.....no chance.

You can also run a repo W-455 intake or an OEM one if you got deep pockets.

 

No chance also with the Torker especially if you run a phenolic spacer under the carb, the ram air breather will not fit either way and if you do it will smash the foam flat and if you motor moves enough under acceleration it will break your 600 dollar ram air breather. You can use a moroso, holley or K&N 14 breather the one with the filter on the top and you can get some ram effect or make a homemade breather like I did with foam but you lose the factory appearance.

 

I run a torker with a dropped base air cleaner and it is tight with the w-25 hood but it definitely works guys period for almost 6 years now.

 

by the way i forgot to add my mistake, I also run a half inch nitrous plate for the entire duration of time.

 

great info guys, I'm in the planning stages of my engine build. I really want full operation of the w-25, not just the hood for looks.

 

I mocked up with a performer to check clearance. Approximately 3/4" needs to be milled from a performer to use the factory OAI. Although, the vacuum solenoid may not clear the hood.
Factory w-455 intake:


Performer:


Side by side:

 

Performer and Torker are the same height.

 

Try to find the old o4b edelbrock they fit without modifications and if you match them and clean them up and cut down the plenum divider 3/4 inch they will run good! especially for a street car up to about 6000rpm. Its worth a try. I will post some pics hopefully today.

 

Sorry, don't mean to steel the thread but was wondering is this the same issue with the small block 350?

 

Performer is the same height as stock. Runners are lower inside which is why you cant use the original style intake gasket with tray. Performer RPM is 2 inches taller and a great manifold.

 

Great pics MX442! Im probably going to go the performer route.

 

I forgot to mention that the performer WILL fit without milling if you don't use the OAI air cleaner lid.

 

Photos not available anymore. Do you still have these photos? Any performance issues after milling down 3/4" off the carb pad? I am going to be doing this to my intake next week.

 

This is an 8 year old thread. Post your own new thread.

 

Yes. The O4B works with no mods. However you do need to do work to make a non stock HEI with the built in coil as they are fatter. But any stock size distributor works including a Holley Hyperspark.