question on 302 heads for my sons 318

[bill paynter]

I pulled a 318 motor out of a 82 dodge prospector for my son
the heads say 302 on them but when I pulled the exh. manifolds off I noticed a small hole at the bottom of each exh. port do all 302 heads have these and if so how do you plug

 

[MopaR&D]

Those are air injection ports for emissions. If I remember correctly my "How to Build High-Performance Chrysler Engines" book says to tap the holes and plug them. I suppose you could try welding them shut and grinding them flat too.

 

[rumblefish360]

Ethier will do.
To drill and tap, go to a size easy to get a decent size larger than the hole.

Welding it up aint so bad ethier.

I knew a guy that shoved aluminum foil in there till it stoped leaking.

 

[camd64]

i have a set of 302's on my 318 and i found some set screws that fit right without having to drill them out. i just had to tap the holes about a 1/4 inch down and i was good to go.

 

[bill paynter]

Thanks fo the info. guys
I've always herd good things about these heads so I was supprised to see the emission stuff on it. thought maybe I got the wrong heads

Thanks again

 

[alan627b]

Just so you know, the holes are for air injection, which was used to improve emissions and started appearing about 1987 or so , when TBI fuel injection showed up on trucks, vans and various Diplomats, etc. You might want to make sure you block off the air injector tube holes in the back of the passenger side head, too. Although as long as the small holes in the exhaust ports are sealed, it shouldn't matter.
Alan

 

[66dartgt]

1/4 inch coarse thread tap and 1/4" coarse thread allen head set screws with a little loctite on them, and you are good to go. Depth isnt that important, just deep enough so the set screws are below the manifold flange. Take a machinists file and dress the area around the plug as well, the metal pulls up a little when you tap.