A couple of different mockups today

[My427stang]

When looking at the CJ intake, my opinion is that the worst part of it is the driver's side plenum area. 

The rest of the intake is pretty normal, but the primary and secondary on the left bank are deep iron bores, near the bottom of the plenum they abruptly end and it looks like the the air has to take a sharp corner.

You can see a modified version in Jay's book, but ultimately I think you need to make those holes oval, so you can get in there to work that plenum transition.  The right side of the manifold seems pretty normal

Keep in mind, the intake is a very good piece, I haven't got in there yet to really determine what I think needs to be done (and if we are going to do ir for that matter)

[427LX]

When looking at the CJ intake, my opinion is that the worst part of it is the driver's side plenum area. 

The rest of the intake is pretty normal, but the primary and secondary on the left bank are deep iron bores, near the bottom of the plenum they abruptly end and it looks like the the air has to take a sharp corner.

You can see a modified version in Jay's book, but ultimately I think you need to make those holes oval, so you can get in there to work that plenum transition.  The right side of the manifold seems pretty normal

Keep in mind, the intake is a very good piece, I haven't got in there yet to really determine what I think needs to be done (and if we are going to do ir for that matter)

My intake not an FE but same type design had the same issue at bottom of the deep side plenum holes.
I was able to use a long shank grinding burr and try to lay back and radius the hole edge to lower plenum roof area.
I had opened up the bores to 1.700 before any radius work.

[My427stang]

Nice pic, my challenge will be if my machinist is willing to cut iron for a reasonable cost.  The guy I will use is pretty talented and a racer himself, so my guess is if he has the tool, he will be happy to do it, but we'll see.

Nebraska is an odd place for performance stuff, not many people trying hard to get things done, and of those, less are actually able to.  There are some very talented guys, but you have to hunt them out and they tend to be extremely busy.  Growing up in Massachusetts, I had to get used to the Nebraska "I'll get around to it" or "Good enough to keep the tractor running" and/or find the good guys.

[Joe-JDC]

AND it is ONLY going to get worse trying to find those folks who will take the time to work on iron heads or intakes!  Not just Nebraska, even here in the 9th largest city in the USA, I have had a very difficult time finding anyone to weld a crack in an iron cylinder head.  Joe-JDC