Factory Exhaust manifold bolt PLUGS !

i think it was on bscene somewhere i read that an older gm lug nut works to thread over the ports in the top of the exhaust manifold if anyone has a specific vehicle i can go in and get the lug nuts for to block these ports i would be really greatful

I THINK THEY WERE FOR 3/4" LUG STUD SIZE & THEY WERE GM...RUSS D MADE THE POST ABOUT IT, YOU COULD LOOK BACK THRU HIS POST TO FIND OUT SPECIFICS......

anyones help please i can find it !!!!

An SAE nut fitting a metric engine?Man that would be a first, but maybe because they are exhaust related?Just a question>BJ

yeah well thats what i have read on here sooooo.....

I have some on my exhaust mani I'll look tomrrow to see what they were on.

finally possibly someone can help

Hey man i just did the weber carb and was wondering the same thing go to your local parts store and get 14mm lug nutz i put them on no jb weld but should have and bam there plugged up

ive since PLUGGED the holes kindof a temp fix im trying to get the other motor tranny and rear ready to go in 2.3 turbo out of a turbocoupe ( THANK YOU WOODLAND ) ill take some pics to showyou guys in a future post

it is a standard size because before the trucks were sent to the u.s. they didn't have all of the emissions. when they get here, the u.s. puts the emissions on it. that is how it use to be. that is what i was told anyway. i believe it is 3/4" but don't take my word for it. i plugged mine about a year and a half ago. if you have a tap and die set it should have a gauge in the kit and you will be able to determine it like that.