Exhaust manifold studs....on the manifold
 

I am going to replace the busted exhaust manifold studs and gaskets. My question is I need to put at least new nuts on the studs that are screwed into the manifold itself, where the Y pipe bolts to them. Does anyone know what size and thread count the studs are? I refuse to pay $3.80 for a nut when I can get a stainless one from my local hardware store for under $1.00 each.

Also while I'm at it, what size bolts can I use where the Y pipe bolts onto the straight pipe that connects to the CAT? It probably doesnt matter since I'm going to have to grind and drill them off anyway.

That cat flange, I used (I think) 3/8" bolts. Grind off the bolts, flat to the flange, and then drill them out with a 5/16" drill bit, and then use a punch to push them through. Or just go to a 3/8".

The manifold-to-y-pipe bolts, I have NO CLUE. Just cut them, and bring them with you to match up.

The studs on the manifold to Y pipe actually look in good shape. The nuts however are another story. Guess I might have to wait till I remove them. Thanks for the info on the other bolts though.

Talked to my mechanic today. He said they are special nuts. Picked them up and looked at them. Yup, they really are special locking nuts. The hole actually looks messed up, but thats how they lock onto the studs. 3.80 a piece....oh well.

The nuts get squeezed so as the bolt threads through them it forces through and stretches the nut out keeping a constant pressure around the stud. Cheap way to make a lock nut basicly. You don't have to pay 3 bucks a pop for them, they sell them at tractor supply, or autozone(although autozone charges quite a bit for them too)

exhaust manifold bolts i am pretty sure they r

m8/1.25/35 flanged head i m getting ready to do all 20 of mine if u got the right tools could do job in 8hrs pb blast the night before great rust buster



ynoT!!

My friend did them for me. It took 10 hours to do it and 2 drill bits cause 2 snapped off clean with the head. He said he also noticed a little pitting on the head on the passenger side (which is weird cause the driverside was way worse for amount of busted studs)
I soaked everything for the last week with PB blaster for him