Technical C4B s, which is the earlier configuration?

I'd like to know which is the earlier production model. I think the one on the left might be the earlier production.


Sorry, the one on the left in the bottom pic.

 

Brad54 may know. I have had one since 1974, but don't know much else about it.

 

they were made with the oil fill on left and right, not sure one was earlier than the other.
Other than that what would be the difference between the 2?
which one will work for you best?

 

For performance ,no difference; I have to machine the one I use because of block and head machining. I'd like to use the earlier one if I can identify it. I never knew anyone who could afford one of these when they were first made, so I never actually saw one until after I got out of the Navy in the 70 s.

 

The unpolished one is the earlier piece - the polished one is like the later non-4 hole c4b/c3b - changed to accommodate the accessory boss on the front....

 

I'm running a C3B and it angles the oil fill to the drivers side, it being newer than a C4B ; I'd say your one with it angled to the p*** side would be the older style?

 

Angled oil fill to the p***enger side is the older (earlier) design.

 

Somewhere I have a 1970 Edlebrock catalog , gonna dig it out and see if it sheds any light on this. Also I took a closer look at the one on my coupe; it's actually a C3BX.

 

I posted this in another thread. From Dec. '65, seems like the p***enger fill would be the original.

 

Not sure if it's the angle but- Are the 4 "barrel" holes all the same size? the unpolished looks smaller from here. Are they for Rochester 4 Jet?

 

Pretty sure they fit just about any later square bore style carb, Carter, Holley, Edelbrock.

 

Found my catilog, it's actually a 1971 issue. It only shows a C4B divider style, with the oil fill to the p*** side. No C3B shown, just the C3BX as a superseed unit ; the X model shows the oil fill to the driver side. No mention of early-late engine type or options on oil fill placement. So I guess the mystrery continues...

 

Check Victory out and see if they have any pictures?

pdq67

 

Thanks for the responses. I seem to remember magazine articles about machining the early 4 hole manifolds so only the plenum divider remained.

Yes, the holes are essentially the same size; they are just drilled and have a very rough finish.

 

i have a C3B with the plenum divider milled down for better up[per RPM air flow.

Hanging on to it in case I build my 283.

 

Have you tried contacting Edelbrock? I believe they're still in business.

 

I talked to them some time back. Not much help on a C4B that I have with no plenum divider at all. They recommended a Performer RPM.

 

I am running the RPM air gap on my 350...much better manifold for that motor, for a 327 or 283 the older ones will work fine.

 

oil tube on p*** side is early manifold. early manifolds had four holes,latter ones had two oval holes. the one pictured with the slot machined into the divider on the secondary side is from 69 or 70 .Ford had holley make a 950 three barell carb to run Nascar to beat their rule on four barrel carb size. they got away with it one year only. so some of the after market manifold makers machined their manifolds to fit that carb. the secondary throttle bore was oval shaped using an oval throttle plate needing the slot to open.