ok I have a late model head year 83 i'm sure bought it from Clifford in 2003 and it has sat in a box since there are 2 holes up front I know one is the temp sender switch and the other egr crap are those 3/8s pipe or metic 13mm and now what is the hole for at the back just behind the 6 exhaust port, and what is the part name and number for it sorry about my writing not an English professor

ok the port at the back is the port for the air injection system that can be blocked off with a flat plate and a bolt you can get the factory block off plate form v8 motors like the 318 or the slant in junkyards they used to be common you can get different size and thread bolts from a hardware store cheap and try them until you find one that fits the hole you want to plug or you can just go to a junkyard and pull the fittings from a slant or v-8 motor from the 80s that should match the threads in the hole you are trying to fill

Are you doing a solid or squishy cam?

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