I am removing the smog pump from my 305 85 elco and need to put plugs in exhaust manifold where lines from pump go to. I saw specs once on here but cannot find thru search. Size and type thrread? Leaving ecm, egr and other items. Thanks.
1/4" NPT pipe plugs. They have to be iron, they are sometimes sold as black plugs. You can pick them up at your local home improvement store/hardware store. I put a little muffler weld on the threads before I installed them.