Blocking EGR passage on maifold

[Twins]

Does anyone have a method to block off the hole(s) in the EGR passage on the Manifold side of a 73 351C? I assume the hole or holes cannot be left open to the air and there is no harm in blocking them?

I plan on changing the manifold at some point when I can do it myself but for now, I would like to block off that "j" shaped area on the stock manifold (or at least the opening (s) and use a square bore to spread bore carb adapter with the carb I have now.

I cant leave the EGR spacer I have in place now on top of the manifold with this adapter as I will likely have clearance issues with the air cleaner system I have now. The adapter is about 3/4 of an inch thick.

Thanks,

Jeff

 

[Omie01]

That is tough to do without some kind of adapter. I am in the middle of reworking an original 4bbl 73 intake right now to accept a holley. The wall of the EGR well interferes with the secondary linkage on a Holley if you try to flush mount it. I had to grind some of that away, and then had to add some weld around the secondary opening to have a wide enough sealing surface for the gasket. I also ground out the middle walls to make it a dual plenum. Lots of welding and machine work! Not sure if I'm going to use it, just seeing if it can be done.

 

[jsbcats]

I'd say bite the bullet and get the manifold changed out. Doesn't take that long if you have a friend helping.

 

[Twins]

I'd say bite the bullet and get the manifold changed out. Doesn't take that long if you have a friend helping.

You are so right. I have looked at this a few ways (adapters, stock carb, custom adapter) and the change is the logical way to go (as someone on here warned me when I first started mucking around with this). Hell, Jpaz did it with one arm. So, I'm going to stop whining, get a friend with a little better skill set than mine, and learn something putting this manifold on. I would of course appreciate any advice and still have some questions (like the whole turkey pan issue. Does it stay or go!?)

Thanks for the reply.

Jeff

That is tough to do without some kind of adapter. I am in the middle of reworking an original 4bbl 73 intake right now to accept a holley. The wall of the EGR well interferes with the secondary linkage on a Holley if you try to flush mount it. I had to grind some of that away, and then had to add some weld around the secondary opening to have a wide enough sealing surface for the gasket. I also ground out the middle walls to make it a dual plenum. Lots of welding and machine work! Not sure if I'm going to use it, just seeing if it can be done.

I'm sure you will do it. I was thinking that making an adapter plate that covers the EGR well might do it. I found one that has that type of bump out to partially cover that well but it is for a 74 460 I believe. Not quite right. You probably could add material onto the side of this adapter at the bump out point which goes from a spreadbore manifold to a square bore carb.

Or how's about just modifying an original EGR spacer? I saw one mentioned but it is long gone. There was also a company selling reproductions of those spacers so you would not have to kill an original but they seem to be discontinued.