79 400ci EGR
 

Hello,

I rebuilt the MC2150 carb on my 79 f350 the kit only came with 2 base gaskets and a heat isolator plastic plate. Im confused if im supposed to use the paper thin gasket under the egr plate and only on one side of the isolator or on both sides of the isolator?

You probably only got 2 gaskets because there was no plastic isolator plate (at least on mine). The egr plate and 2 gaskets are the only thing between manifold and carb. In your case, you will need 3 gaskets. Gasket on manifold/EGRplate/Gasket/Isolator/Gasket/then the carburetor

The gasket between the carb and EGR/spacer plate is much thicker than the gasket between the EGR/spacer plate and the manifold.

1978/79 F100/350 & Bronco 351M/400:

D5HZ-9C477-A .. Gasket-Carburetor to Spacer Plate-thick (Motorcraft CG-539-A).

D7AZ-9447-B .. Gasket-Spacer Plate to Intake Manifold-thin (Motorcraft CG-488).

The egr gasket is not included in a carb kit. It is a special high temp gasket that you will have to get through your local parts store. Take the plate with you because there are many different ones.

Don't use any of the base gaskets that come with the kit. The manifold-to-spacer gasket is woven with steel. The spacer-to-carburetor gasket is about a quarter inch thick. Each must be bought separately.

So just to get this straight. The spacer to manifold gasket is MC# CG488 and the spacer to carb gasket is the thick one with the plastic inserts around the mounting studs MC# CG 359 A. These are the only 2 gaskets I need to mount the plate and the carb, correct?

Thanks,
Dave

That's correct. There's a third gasket for mounting the EGR valve itself to the spacer plate; it's made out of the same material as the spacer-to-manifold gasket.

Great, thanks. I pulled my carb and spacer today in search of a vacuum leak and maybe a burnt out spacer but the spacer looks in great shape. Where is the common place for these to burn out? I don't see anything except some discolouration from carbon.

They usually burn out on the manifold side (bottom), near where the exhaust comes out of the manifold. You might try checking for flatness with a straight edge and tiny feeler gauge. The cast iron ones burn out a lot less frequently than the aluminum ones, but it can happen.

K, thanks, I'll check it for flatness but I think it's ok. As I said, looks to be in perfect condition. Truck only has 46,000 miles on it. There is some evidence of carbon staining on the outside of the plate on the exhaust passage side so I'm suspecting the gasket may have been not so good on that side causing a vacuum leak. Can I still get these gaskets from the dealer?

Not sure about the dealer; I usually get Fel-Pro brand gaskets which you should be able to get through Rock Auto or other places.

The factory installed EGR/Carb spacer plates were aluminum. Hot exhaust gasses caused them to melt internally. They also tended to get plugged up with carbon.

FoMoCo 'service part replacement' plates were cast iron. There are two different types of EGR valves, two different types of mounting gaskets.

I called the dealer today and they said the spacer plate to intake gasket was obsolete. I then went to the parts place and bought a standard motor products gasket kit. When I looked at it the spacer plate to manifold gasket is paper. The only one listed on Rock auto is the one I bought local.

Any idea who makes a proper replacement gasket? I thought they were made out of a silver thicker metalized gasket material.

You're right on the material, and you definitely do not want to use the paper-thin gasket. It will burn out in quick order.

When I look up a '79 400 (are we talking about the same engine?) on Rock Auto, I see Fel-Pro 60332, but it definitely looks like paper.

http://www.rockauto.com/getimage/get...67-0&width=450

That's pretty surprising. I can't tell if it really is paper or just a bad picture. You might call them and ask. If not, Napa or Carquest tend to be better about hard-to-find-right parts. If nothing comes out of that, you might take the risk and see how the Fel-Pro paper-looking gasket seals up; worst case you can make one out of header gasket material.

Post 2 = Motorcraft CG-539-A

D7AZ-9447-B .. Gasket-EGR/Carb Spacer to Intake Manifold (Motorcraft CG-488) / Obsolete

Applications: 1977/79 FoMoCo Passenger Cars/F100/350 351M/400 / 1978/79 Bronco 351M/400.

GREEN SALES CO. in Cincinnati OH has 9 = 513-731-3304 / 800-543-4959.

CHUCK SPAETH FORD in New Ulm MN has 14 = 507-354-3179.

PARTS INTERNATIONAL in Farmers Branch TX has 27 = 972-241-8730 / 888-727-0418.