Identifying odd port on 289 intake manifold

CBaron

Member
Apr 12, 2020
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Austin
We're working to get my son's 65' Mustang up and running. We've been troubleshooting an exhaust leak and blew spoke into the tail pipe to look for what we thought would be an exhaust manifold leak (and I think we may have found it at the donut collector. However, we also noticed smoke coming from what seemed to be the manifold riser plate gasket. Once we pulled the carb, we noticed this. Can someone help me identify what this "side port" is on the left? I've not scene this before and can't located anything like it searching the internet. You can see that the gasket didn't quite cover it up when everything was installed.

Thanks,
CJB


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dennis112

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May 15, 2005
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Amish Wonderland of Central PA.
That manifold came with a special spacer, which IIRC, had an EGR valve attached for emission purposes. It may have been just to heat under the carb. The spacer would be approximately 3/4 to 1" thick and it will be needed unless you locate/build some type of block off plate. You may even want to consider finding a different intake manifold.

BTW, most carburated Ford cars used some type of spacer under the carb but most of the older ones do not have the port in question.
 
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MustangIIMatt

I need something stupid to play with
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What @dennis112 said is correct. That manifold looks like the one used on the mid 80s 5.0HO during the brief period when it was carbureted.
 

CBaron

Member
Apr 12, 2020
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Austin
Man, you guys are some night owls! Thanks for the replies...

Here's our story with this: We picked the car up a few months ago and it was running enough to drive it around the block. But the car had sat up for about 4 yrs. It idled and ran fine at the time. But in our around the block excursion(s) we ended up sucking up some bad gas. Thus we had to rebuild the carb, which I wasn't really keen to do. But it all went pretty well. With everything reinstalled we are trying to get it to idle properly enough to not stall when we put it in gear (its stalling out right now). But whatever....I swear that our exhaust leak started once we put the rebuilt carb back on. Just yesterday we notice this issue I posted about. I think this is my exhaust leak, right?? Could it have an effect on how the car idles?? How was it running so well (no exhaust leak, no idles issues, etc..) before?? When we rebuilt carb, we did replace both upper and lower carb spacer gaskets.

Here's the video I sent to my Ford buddy yesterday.
View: https://youtu.be/KFA-sqsnoto
 

MustangIIMatt

I need something stupid to play with
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Mar 7, 2002
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Man, you guys are some night owls! Thanks for the replies...

Here's our story with this: We picked the car up a few months ago and it was running enough to drive it around the block. But the car had sat up for about 4 yrs. It idled and ran fine at the time. But in our around the block excursion(s) we ended up sucking up some bad gas. Thus we had to rebuild the carb, which I wasn't really keen to do. But it all went pretty well. With everything reinstalled we are trying to get it to idle properly enough to not stall when we put it in gear (its stalling out right now). But whatever....I swear that our exhaust leak started once we put the rebuilt carb back on. Just yesterday we notice this issue I posted about. I think this is my exhaust leak, right?? Could it have an effect on how the car idles?? How was it running so well (no exhaust leak, no idles issues, etc..) before?? When we rebuilt carb, we did replace both upper and lower carb spacer gaskets.

Here's the video I sent to my Ford buddy yesterday.
View: https://youtu.be/KFA-sqsnoto
I don't know if that's your only exhaust leak, but there's definitely going to be one there. The only way I can figure that there wasn't one there before is if the previous owner was running a wider and thicker gasket to block off the exhaust port, but that's going to end up being a temporary fix at best.

Your two best options to correct the issue will be to find the EGR spacer plate for it (likely a salvage yard or Ebay scavenger hunt item), or replace the manifold with a non-EGR manifold (which is a chance to upgrade to something better from Edelbrock, Weiand, Holley, or hell, these days even some of the Chinese knock-offs are pretty good.
 
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