Good question. How much difference is made ind match porting the intake ???

For Mopar intake porting the other guys here should share their experience.

I can share what I know from comp heads and pro stock stuff.

In many cases it's good to have the intake opening very slightly smaller then the head opening. The small lip left helps tune the shock wave that travels the port.
On a head that may have too large a port for the engine combo, .. leaving the port opening small can also have a very good effect on port velocity. We used to run oval port intake manifolds on square port bog block Chevy heads and pick up .3 - .4 et all the time.

As for the rest of the manifold, .. porting & tuning on an all out head / intake combo is critical. The head & manifold together form ONE intake runner right? So the intake runner cross section & volume is just as important as the runner in the head.

On many combo's the gasket area, where the intake meets the head, becomes the smallest area of the entire intake runner.
A properly designed intake runner should not have the same size ( area & cross section ) all the way down. Just a strait pipe from the plenum to the valve wouldn't make power.
There has to be a little venturi in the port where it get's a little smaller to effect air speed. How far up or down the port this is located depends on the combo.

If you really want to know the entire airflow story in an engine, ..
flow the exhaust port with the header that it's going to run with, .. and the intake & carb on the intake side.

When you get this far into a project, .. it's a VERY good idea to turn the head around on the bench, push the air out of the bench into the intake, .. so you can do a velocity map of the airspeed coming out of the valve.
This is a good time to do wet flow since the set up on the bench is the same.

Curtis

And for anybody interested, my SF-110 is now for sale under the Tools and Equipment For Sale section of the board.

Curtis:
I build Jr. Drag engines and I have had similar experience with the ports and intake manifold. I made my intakes out of aluminum stock on my lathe. I would taper bore the intake at about 1.5 degrees over a 5" length.
I only used round ports with the intakes for the ease of doing the ports. For example: I used a Mikuni carb with a 1.600" throttle bore with the valve seat having a I.D. of 1.500". I would turn down fender washers to the appropriate O.D. and use them for templates to keep the port shape. The Super Flow manual showed an ideal port shape and I used that as a guide.
I guess now I will have to try this on some old V-8 heads and learn from there.
Thanks for the info.

I have a SF110 that I haven't turned on in a couple of years. I'm seriously thinking about starting to flow Eddy carbs though. I doubt I'll ever get the itch to do heads though. I tried that once and gave it up very quickly! Way too much work, not to mention, I didn't have a clue what I was doing.

I got a six pack manifold from muscle motors several years ago with some 906 they ported. They offered to quote clean it up for a hundred. So I had them do it. I've never ran it. So I don't know if its worth while gain or not.
I have a Eddy dual four intake that susposed to be the same as the six pack just a different top or so I've heard. I should look down the two and see what can just be visually observed in difference if anything.