They come up very very rarely. Last one I saw for sale two years ago went for $3500. I would take a guess and say it would likely work really really well.
Chances are it is a nock off of a HM B2 manifold laying in someones archives even then, with a Shelby logo on it?
If there was a manifold to copy and expand upon for the Cleveland, I'd vote that's the one. Anyone who sees it wouldn't argue.
I'm currently running the 289 version of that manifold on my 347 using 2 1850's. Having run Webers as well, I'd opt for the 2/4s, given a choice. It has such a nice powerful torque through the rpm range, and when the secondaries open it lights the tires on fire with this huge womp, and you can run around all day need be with just using one two barrel using, get this... #59 jets!
The Webers and I are currently on a lovers holiday. Maybe we'll get back together, maybe not?
Not that the Webers are shabby by any means, but all the problems of a carburetored IR intake just go away with the 2/4. I haven't burned my eyebrows off with the 2/4's yet either like with the Webers.
I told you all to never look down the throats of the Webers and rev them right? Gee-ze, kids?
As far as a single 1050 on THAT manifold working better is simply hog wash. That may in fact be some left over Communist brainwashing infiltrating the high performance car after market industry of the time. The press was highly infiltrated then.
It is simply too ridiculous of a statement to take seriously. It sucks with a 750. How can it be better with a 1050? Impossible.
I can't really tell from that picture if this is a single or dual plane manifold although there are the slightest hints that it is dual plane to me.
Even if it isn't, the 427 Tunnel-wedge is single plane as well. I never heard anyone claim that it doesn't work very well?
It has resemblances to the Boss 302 dual plane, which has the same type of round port runners and carb locations.
Since this was a study likely for possible production, I would bet it is a dual plane.
Somewhere around this time Ford pulled the plug on the high performance program. There was a lot of initial internal panicking. All efforts needed to be concentrating on emissions certification and the immediate dropping of all high compression engines.
Timing for the high performance Cleveland was bad. Boss 429 items seemed to have had priority since they were done first.
The 2/4 B9 manifold was made in enough numbers to have survived. I remember it being on the HM price list. Never saw the Cleveland parts listed though.
I wouldn't mind leads on locating one if anyone was so kind to divulge that.