(I looked through earlier threads that discuss the F351, but did not see my question answered).

I bought home a '71 last week and it has an Edelbrock F351 intake manifold on it. There is no further designation. It looks like some (perhaps later ones) had 2V or 4V designations.

Does anyone know what heads the non-designated intake was designed for? If I presume wisdom on behalf of my predecessor owners, then it's 4V. I have 4V heads (open chamber? With the dot next to 4).

Perhaps Edelbrock started with a 4V intake and then started designating which one was which when they later made a 2V model?

It has a Holley carb on it. I haven't looked around it with an inspection mirror to find the model number on that yet.
Original Post
The F351 intake is a 4V intake.

The Edelbrock intake runners are about 1.5 inches in width and 2.2 inches in height. This is the size of the 4V intake port at the push rod bulge. The 4V intake port is approximately 4.3 sq. inches at its inlet; its dimensions are 1.75 inch width by 2.50 inch height. It was designed to match with intake manifolds having high volume runners. Yet by the push rod bulge, which is only 3/4 inch into the port, the dimensions are 1.48 inch width by 2.21 inch height. This is about 3.27 sq. inches; i.e. the port’s cross sectional area decreases by one full square inch. Thus the first 3/4 inches of the 4V intake port, the section between the intake manifold flange and the pushrod bulge, is a funnel shaped transition from intake manifolds with high volume runners to a smaller intake port having about 3.15 sq. inches average cross-section. The Edelbrock manifold ignores the funnel, and attempts to keep the runner to port transition at more of an even cross-section, rather than fanning open to mate with the entire intake port. This really has no detrimental effect on the operation of the induction system ... but at the engine speed the intake is designed for it doesn't seem to help either.

The heads are most likely 1971 quench heads. As I remember it, the dot was added early during the 1971 production run. Only the earliest 1971 heads were cast without the dot.

Compared to the current 4V and 2V versions of the Edelbrock Performer mine has the carb mount of the 4V (with 2 sets of mounting holes) and the choke stove mount of the 2V (the current 4V does not have a provision for the choke stove).

Last edited by perryh

just recently documented, there is an F351-2V

note the height of the runners adjacent to where the choke stove would be

 

F3512Va

and the underside shows the same PN as the Performer 2V

F3512Vb

IIRC the F351-4V had a different PN (or none) than the successor Performer 4V which there may be 2 of, with & w/o EGR provision

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Last edited by 4vandproud

yours appears to be a 4V version by the size of the runner lumps

(the 4V ports are taller than the 2V ports)

i came to the same conclusion, Edelbrock only had the F351 until they introduced the 2750 2V version and by that time they had started a part number system other than the simple alpha-numerics they were using ... ?

Last edited by 4vandproud

I've done some wrenching since I originally posted this.  I definitely have closed chamber heads. 

 

20191110_022505

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it might just be the pic but it appears to show a head locating dowel sunk into the head bolt hole on the upper right corner? maybe check them all (lower end holes)

Yes, those stayed on the block on the driver's side, but stayed in the head on the passenger side.  They were just barely stuck and popped right out.

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