blocking off exhaust holes on rear of 5.0 heads?

[MustangBill87]

Whats up? I have an 87 GT that I am converting to a carb set-up for track use of course. My question is this, what are the holes on the rear of each cylinder head for and is it ok to plug them or should the be recirculated to the exhaust. Thanks for your help!!!

 

[1991notchbackLX]

Pull your smog equipment and block them off if that's your intention. I've heard of everything ranging from just buying some bolts from a hardware store to using two old spark plugs with the ceramic broken off to plug them up.

 

[cenok is family]

they are for the smog pump. get a couple metal pipe plugs or bolts to plug them. make sure they seal off all the way

 

[MustangBill87]

Thanks for your help, did not want to hurt the stang so I figured I would ask the seasoned veteran's.

 

[Chrome_Rust]

I have a set of E7's that I am porting, I welded up the port in the exhaust and i welded up the holes in the back of the heads. Guess you could use a pipe plug...

 

[liljoe07]

5/8-11 thread set screw or bolt is what you need.

 

[-Nick-]

make sure you are running a open breather on the valve covers then...

 

[cenok is family]

make sure you are running a open breather on the valve covers then...

he's not talking about the PCV system. plugging the holes for the smog pump has nothing to do with crankcase ventilation.

 

[2000xp8]

Ford sells the proper plugs to put in the holes, they are only a couple of bucks and are physically available at the ford dealer.
Unfortunately i forgot what i asked for when i got them.

 

[1991notchbackLX]

Ford sells the proper plugs to put in the holes, they are only a couple of bucks and are physically available at the ford dealer.
Unfortunately i forgot what i asked for when i got them.

thermactor plugs?

 

[liljoe07]

thermactor plugs?

Yup

 

[Joey7508]

napa in my town sells thermactor plugs or did. You can order them thrugh cjpony but they are 12$ a piece

 

[black'vert]

just take off the smog crossover tube, chop the ends off and install them on the opposite heads .....effectively flipping them around so the holes are blocked by the backside of the flange.

 

[hubstang]

I found these block off plates that bolt on from LMR.

SVE Smog Port Block Off Plate Kit 5.0/5.8 - LMR.com

Block off the smog ports on your Mustang 5.0 or 5.8 not originally equipped with smog equipment using this SVE smog port block off kit!

lmr.com

 

[Exrace89GT]

Make sure you run a tap in to clean the carbon out of the threads.

 

[Mustang5L5]

Those things were totally clogged up on my e7s. Definitely chase the threads with a 5/8-11 thread cleaner before attempting to screw anything in,m

 

[tsiemens]

I bought the plugs not knowing how bad the carbon build up would be so I ended up reversing the plates as another guy here mentioned

 

[mattys91gt]

I bought the plugs not knowing how bad the carbon build up would be so I ended up reversing the plates as another guy here mentioned

did this work for u I'm still getting a leak