Woohoo! Just got lucky and picked up good used M1 intake manifold P4510016 off my local craigslist that I plan to use with my upcoming 408 build. It came with the bulk of the install kit hard parts, but not the EGR plugs. There are 2 spots I'd like to plug - the very rear of the intake, where the EGR tube attaches and along the cast portion of the EGR tube as it makes its way to the intake plenum. Does anyone know right off what the thread size is of these holes, so I can find a plug for them?

 

Anyone with an M1 intake with EGR provisions have any thoughts on this?

 

Just make a blank plate to cover the EGR port.
Use some gasket to bolt it on.

 

I'm aware of the plate to plug the EGR port and I plan to take care of that. The main issue I have is that there is a threaded port in the cast-in EGR tube of the intake manifold that leads to the intake plenum that must be plugged - if not, I can see one heck of a vacuum leak. Was just wondering if other owners of the M1 EGR intake know what thread size/pitch that plug is?

 

That port leads up to where the egr valve bolts on. if you put a plate over that spot, it will cover any holes into the intake. So, no vacuum leaks. (but, a nice plays for wasps to make a nest...... at least, until the engine warms up. )

 

There is another port further up the cast-in EGR tube of the intake that has a spot for a threaded plug. I can see a leak there for sure, regardless if there is a plate over the rear. Perhaps a photo of the intake and area in question will help?

 

Post a picture of the port you need to plug. If it's the same as the one on my EGR kegger I can measure it for you.

 

Please see the attached photo areas marked in red. This is where I'd like to place threaded plugs, but just need to know the thread size/pitch.

 

Congrats on the M1 AtomicDog!! I don't have the EGR one, yet with a visual look at your picture it kind of resembles similar size to the heater outlet size. Shown here to the left of the coolant pipe.




Have you thought to call Mopar Performance to ask? I have in the past and they were great. Any chance you can just go to autoparts store to have them pull the EGR fitting to test fit (bring the M1 with you)? Sorry if that is dumb suggestion as I don't know what the EGR fittings look like anyways.

You'll get this in though, I'm sure of it!

 

Three spots need plugged. The two you have highlighted, and also the port where the egr valve actually sits. Two of them are more than likely pipe threads. Should be able to get plugs at any hardware store. (take the manifold in with you....) have to make a plate for the valve area.