Distributor won't clear 2 X 4 Intake

I've got an old low rise Offy intake that excepts Holley carbs and I have two 450 cfm's off a tunnel ram. It doesn't look like the distributor will clear the rear bowl, without a large carb spacer. What's the common fix for this ?

 

Carter carbs?

 

afb's/edelbrocks

 

I really want to run the Holleys since I have everything here and ready to go.

 

A Mallory Unilite has a pretty small cap, so it'll give you some extra room, but it looks like you won't be able to use big Holleys on it anyway if they have bowls hanging off the back.

 

Offy makes carburetor adapters that rotate the carburetors 90 degrees. They also make the linkage for the adapters. I can get everything you need.

Dan Marvin, Owner
Exeter Auto Supply

 

Turn carbs 90 degrees?

 

Here is a picture from the Offenhauser catalog of the adapters and linkage.

Dan Marvin, Owner
Exeter Auto Supply

 

When I flipped them today for a look see it looked like the throttle shaft would interfeer. I guess if offy makes an adapter for the 90* flip it must move it to one side or something. Here I thought this was a no brainer..lol

 

How do I know if it's a 360 or a 180 manifold ?

 

What is the part number on the bottom of the manifold?

 

It looks like you have a 5253 manifold for a SBC which is a 360 degree manifold. 180 degree manifolds have a divider running the length of the manifold. Normally, 180 manifolds are dual plane manifolds where half the carburetor supplies one head and the other half of the carburetor supplies the other head.

 

360 degree manifolds are wide open under the carb. 180 manifolds have half the runners fed by one side of the carb and the other half fed by th other side. 360 are good for wide open horsepower where 180 produce more torque and are usually better for a street car.

 

the 360 manifold on a bbc you can just rotate the carbs 90 degrees

 

Ok I just went out and got the part # and it is a 5253 but I also tried something else while I was out there.
I put a 500 cfm Holley 2 barrel on the rear carb spot and it will clear the distributor cap. What's your guys take on that running it with a progressive linkage off the front 450 ? I think it would work and being only 50 cfm difference not be far off.

 

Interesting......Is your 4 barrel vac or mechanical secondaries?

 

they are mechanical

 

The key letters here are AFB. You will be able to make it work with the Holleys, but I think it unlikely that it will ever be as good as a couple of properly sized Carter (or Edelbrock) carbs. Sometimes, you just have to get the checkbook out and handle it....

 

Sometimes it would be nice to be able to go back to work, since I've been out on comp for 2 1/2 years.

 

The cfm rating on the two barrel is arivied at with a greater vacum drop than with the four barrel. This means that a 500cfm two barrel will not flow as much as a 500 four barrel at the same vacum drop. There is no direct compairsion that I know between two and four barrels

 

According to Offenhauser, 2 holley 4 bbl's will not fit that manifold, no matter the carbs are positioned. My concern with using a 500cfm 2bbl is a drop in manifold vac when the 2 bbl opens up.

 

You Can Get A Dist. From A 85 Up Tune Port And Use It. That's What I've Got On My Big Block. It Has An External Coil And A Coil Wire So I Doesn't Need Much ROOM


Reggie

 

I was reading that about the intake only taking AFB's, the bolt pattern lines up on the Holleys and the bowls clear in the middle just not on the cap in the rear.
Is that tune port distributor smaller than a points, because that's what won't fit now ?
So about this vacume thing, I wonder how much difference there is ?

 

It would be the same except for the hei cap would be taller. I guess you could run a non hei cap. I also hope you have better luck with the 450s than I did.

 

I Have the same setup on my 48 ford and a mallory unilite dist. fits just right. Bob Myers SD

 

A friend hat that intake on his Camaro way back when, he used a Unilite but had spread bore to square bore adapters on it. I think the new MSDs are about the same size.

 

got a picture of that ?

here's a couple pictures, one with the 4 barrel and one with the 2 barrel, as you can see I would need a 4 inch spacer for the 4 barrel carb to clear the cap

 

How 'bout one of these?
http://web.archive.org/web/20060810112840/http://www.nrcperformance.com/index.html

 

Nice design but not the look I'm after, for the price I'd just go with the AFB's.
This isn't a killer race motor just something that runs good and fit's the look of the car is what I'm after.

 

MSD has a small diameter pro billet distributor i have one in my boat.