1988 E150 5.0 engine vin N.
All the local parts stores say to use Fel-pro MS-93834 upper gasket set but it does not fit..
RA lists the same Fel-pro gasket set but they also have a
AIRTEX/WELLS 1G1174 that is shaped different having oval shaped holes.

Fel-pro says Alternate/OEM Part Number(s): E5TZ9H486A
More Information for FEL-PRO MS93834

Airtex says Alternate/OEM Part Number(s): 250006, E8TE9H486AA, E8TZ9H486A, PG7
More Information for AIRTEX/WELLS 1G1174

1988 FORD E-150 5.0L 302cid V8 Plenum Gasket | RockAuto


The Airtex gasket would restrict air flow.... Any suggestions? Maybe check with Ford? I doubt they have one for a 1988

here is a pic with the gasket on the intake.


Here is a close up where it doesn't fit


Here is what the gasket and intake looked like when i took it off

 

As long as the outer flange is covered by the gasket, I wouldn't sweat that inner flange. It's not going to affect the performance. Either Felpro got lax on their QC or Ford changed the casting slightly during production.

 

Did you check the fit on the plenum? Same results?

Might want to try a different brand/manufacturer?

What you have, is kind of what you removed.

Maybe add some RTV to the "missing" gasket area on the flanges, to create a seal?

 

if there is a leak between the intake runners it will run like crap

 

Many years ago I was rebuilding a 2.3L in a Pinto. I ordered a full engine gasket set from JC Whitney listed as "OE equivalent". What I received was a Ford labeled box full of gaskets with Ford part numbers. I was shocked as the price I paid was half the cost of a set from NAPA at the time. They all fit perfectly as you would expect. Kinda sad that with today's ISO2000 certification we need to "hand pick" our vendors.

 

Edit,, Wildman, thanks for the tip on connecting the tube to the EGR first. I had the EGR bolted on hand tight and the line was at just enough angle where the nut would not line up on the threads so i followed your advice and it worked great!
Not finished putting it back together yet but the rest is going well. Once back together I will need to replace the valve cover gasket on the left side, I thought I would get the hard stuff out of the way first!

It should run much better... one clogged vacuum port on the throttle body and the broken gasket that left a small gap on the outer edge as well as the runner. New TPS and EGR, The only part I have left is the O2 sensor i bought last year...

I was looking at the cat since the doghouse is off and it looks kind of bluish like it has been running very hot... I was getting about 10 to 12 MPG before this work and it smelled a little rich on cold start up but no black smoke. The O2 sensor in in front of the cat.. If the cat was removed temporarily just for testing, since the O2 sensor in in front of the cat, that shouldn't cause any problems?


Well I called my local ford dealer and they said they could get it but it would be $28 plus shipping...
I ask who had it and they said a dealer 50 miles away. I called them and they said $5 if i pick it up. i had some business to take care of in that town anyway so I went and picked it up today. They looked almost identical but the Ford gasket was a good bit thicker. If you held the felpro gasket vertical at one end, it would just droop over. The ford gasket didn't. Though they looked almost the same, the ford gasket fit much better.



Felpro


If you look closely at the bottom pic of the Felpro fit, you can see the outline where the old gasket didn't quite fit either but did cover it half way.

Well I learned something which helped. Originally I used a little permatex black #2 on the outer edge of the bolt holes to help keep the gasket from sliding around and installed 2 threaded studs so I would have to sit the plenum straight down, one stud in the center and one at the rear of the engine thinking I wouldn't be able to reach one if I put it in the front. SO I got the plenum in place and started the rear bolts. when I got to the front the bolts wouldn't go in because the gasket holes were just a little too far forward. I took the plenum back off and got the idea to use a razor blade and cut the front holes out a little towards the back. That made the gasket fit even a little better in the problem area.. The next try, everything went on fine..

The red circles are the front holes while the purple are the rear.

 

Don't see why, All that air starts out from the same source upstream. and the fuel gets added downstream.

 

OK, don't believe me.
Experience is the best teacher.

 

Didn't say I didn't believe you. Seen weird **** happen too. This to me is no different than having an open spacer under a 4 hole under a 4 bbl carb. All the plenum volume gets drawn into the engine. Shouldn't affect how it runs.

 

it does.
and
it is not the same

 

Well all i can say is it seems to run much better now. OF course I cant solely contribute it to manifold gasket because I cleaned the throttle body, plenum, changed TPS, EGR, and rerouted the PCV valve. It is still not quite right but I haven't changed the O2 sensor either.
It is a lot quieter but that is in part because before the doghouse was sitting on top of part of the carpet.

It does feel much like a different van though... That could be because I painted the valve covers though!

 

Don't forget to rotate the battery caps, fill the blinker fluid reservoir and change the air in the tires...

 

Here I go again...

An open plenum carb spacer will affect air flow as will different height spacers.

If wanted a common plenum, it would have cast it as such. It's hard to believe FEL-PRO would offer this crap. I guess it is just like any other modern vendor, cheap sh!at to make money.

 

Yea, that always makes a big difference in running/performance......

All the other "little" things you did, could have save a lot of time and just painted the valve covers to start with.........

.........But, what color did you paint them? The True dark blue?

Any other color, besides chrome, might make a running issue???

 

Well I bought a can of the True Dark Blue and then thought, everything else is ford grey. So I went with grey. If I had been removing the lower intake, I probably would have went with blue. In a way I wish I would have used the blue that way I would mark all the work I do! And now a new oil pan and gasket may be in the future... So blue would have looked good..

I washed it underneath and as of the first day driving the van, there are a couple of oil pan bolts that want to slowly drip oil. The front of the oil pan is rusted pretty good and I have hear of them rusting through. SO if I wind up replacing the gasket, Ill probably just replace the pan too and paint it blue!! I am sure I will have the valve covers off again some time, well hopefully not for a few years..

Assessing the oil pan gasket,,, IT appears to be a black rubber gasket.. IT appears that someone either tried to fix a leak or had the timing cover off, I hope timing cover because that would mean they might have changed the timing chain and gears.. There is black RTV? globed on the front of the oil pan under the timing cover as well as down 2 or 3 " down the side of the oil pan. If I am correct, the front of the oil pan has to be lowered in many cases to get the timing cover off??
That also helps to indicate the actual mileage. I have owned several old Fords and never changed a timing chain till well over 100k miles.. But then again it could have been a water pump and they broke some bolts and had to change the timing cover..... But that is the first indication of work done on the engine that I have found...

I did have a heart stopping moment though when I cranked the van after finishing the work... It had sat for about a month and the doghouse was off... It had a very loud knock that sounded like from the lower end. It went away within 3 or 4 seconds and has not done it since but the longest i have let is sit without starting it is 2 days.. The oil had just been changed when I bought the van and I changed it again a few months later so if there had been any additives in the oil I should l have found out by now.. Now less then 100 miles ago and just before I started this last work where it sat for a month, I had the oil changed at a shop. They used a small short house brand oil filter and 5w-30 oil.. I had 10w-40 in it and a Motorcraft filter..

In the past the engine usually started within 1/2 turn of the engine and jumps right to a very high idle. Now it still starts the same but doesn't seem to jump to as high of an idle.
I had a GMC van with a 350 and always knocked on start up. After much research it seems that was a problem with certain year 350s. GM's solution was to change something in the ECM where the engine had to turn over a few times before it would start giving the engine time to build up a little oil pressure. I have never heard of that kind of problem with a 5.o though...

"Any other color, besides chrome, might make a running issue???"
ORANGE