Vintage Mustang Forums banner

Holes in back of my heads?

563 Views 6 Replies 5 Participants Last post by  TheShagg
I was about to blow a hole in the back of my head trying to figure out where this exhaust leak was coming from. It turns out there are 2 holes in the back of my heads blowing out exhaust. I couldn't feel if they were threaded or not due to temp., but the motor is an 87 lincoln roller 302. Anyone know what these holes are for? Thanks - Chris
1 - 7 of 7 Posts
They most likely are EGR holes, part of the SMOG setup. Ford sells plugs for them. One hole on the back of each head, right?
Those are "Thermactor" ports. Where the old (Lincoln) fresh air pump pumped air into the exhaust ports. Emissions control junk. There are many fixes, but I think the best is to get 2 plugs at your local Ford dealer. Someone posted the exact Ford part number IIRC a while back.
I had the same problem with my gt40 heads so I went to Home Depot and bought a long threaded bolt type thing, cut it, and plugged it. I also put a groove on the plug so I could get it out with a phillips head screwdriver if needed. It only cost me a couple of dollars total.
You mean that Lincoln was still using this same system in 87? LOL! I remember driving two 1/2" freeze plugs in the back of a '70 460 out of a Towncar before installing in my 67 FB ca. 1980!
yup! No crap! Ok, so I can just plug them? Do they have any advantage? I was hoping they were for O2 sensors! I would have had an efi setup on there by the weekend! thanks - chris
nope, wont work for 02 sensors. As everyone said they are for pumping air into the exhaust. Plug at will, no harm done.

As for 02 sensors just buy some bungs and weld them on .
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.