EFI rough idle/EGR block off bolt size?

I have my 302 HO swapped into my bronco with my RJM harness. It has a very rought idle. It ran ok last week when I started it up for a few minutes. Today I finally tried moving it around alittle. Now it has a very rough idle. If I let it just ide sometimes it shuts off. I elimated the EGR with a homemade block off plate on the plenum. I didnt get the plate on the back of the head installed. Does anyone know what size bolt it takes (also is it a tappered thread)? Is this why it is idiling rough? I check the codes, it only pulled the "soft" codes-81,82,85,84. Any help would be greatly appreciated. Also my oil pressure guage isnt working. The engine ran great before I pulled it out of the doner car. Im hoping someone can help! Thanks again!

5/8" 13 tpi comes to mind on the thread. You need to make sure you have oil flowing before anything else.

Do you think it is running rough bc those plugs arent in the back of the head? I didnt think the holes looked that big.

statella43 said:

Do you think it is running rough bc those plugs arent in the back of the head? I didnt think the holes looked that big.

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Nope. The worse they'll do is give you a big exhaust leak.