I have a Clifford 6=8 intake manifold on my 300 six with a 2-V open adapter. Should the carb be installed with the throttle plates side to side or front to back? Also, which size 2100 is considered the best size for a stock engine with Comp 260 and cam EFI headers? As always, many thanks to all.,...jack

 

I prefer to mount them with the fuel bowl facing forward.

As far as the size goes I would stay on the smaller end of the 2100 size range. I would go with something in the 1.01, 1.02 or 1.08 size as my first choice. I would not go bigger then the 1.14 at the most. I would stay away from the 1.21, 1.23, 1.33's unless you already have one and just wanted to try it.

 

Tedster9 -- Thanks for the Holley / Autolite jet information. That article make the jet subject a bit clearer. What is the most confusing is the numbering system as apposed to the true jet hole size. This will sure help in setting up a 1.08 or 1.14 2100 / 2150 carb. Another question I need some feedback on is, do you think the Autolite 2150 is that much better of a carb than the 2100 for a general cruise around town F250 with a 300 & C4? This is just a stock motor with headers, dual 2" exhaust, Holley 2300 2bbl carb. Soon to get my recently milled out stock log intake that will take my 2300 or a 2100/2150 and a Pertronic Igniter 1 module & flame thrower coil. Also do you have a 1.08 or 1.14 2100/2150 carb that you would part with?

 

in my experience, for what its worth, i have found a 1.14 2150 to work pretty well. they're getting more and more difficult to locate in decent shape...around my stomping grounds anyhow.
i have tried larger and smaller, but i prefer the 1.14, personally.
of course i say that, and in the same breath, i'll say that i'm about to swap over to a dual carb clifford manifold with twin TBIs lol.

be sure you have some means of warming up the floor of the intake. a hot ignition will definitely help, but without proper atomization, fuel distribution in the manifold will suffer greatly. end result being 2 cylinders running on the rich side, 2 running close to ideal, and the outer 2 running lean.