BenJammin

Digging in and pulling what is left of my exhaust, I found the studs were pretty much gone and one broke off. Any reasons I cannot just drill these out and put a long bolt through?

Secondly, what is this little flapper in my exhaust? What does it do?

Olds Scott

Bolts can be removed with an EZ out, penetrating oil and a lot of patience. The flapper thing is the heat riser that helps the engine reach operating temperature. The one you have is frozen like mine. Remove and soak in penetrating oil for a few days and with luck it will free up. Check to see if the bi-metal spring is still attached to the other end. I am going to use an aviation penetrating oil called Mouse Milk to free mine up. Good luck

Olds Scott

If you get the heat riser freed up than soak it in acetone to clean off the oil and only lubricate the riser with dry graphite to keep it from sticking again.

BenJammin

the flapper is free and isn't frozen up luckily. I do not see or feel the resistance of a bimetal spring. the flapper just flaps around without any resistance. Looks to me like about 10 horsepower if i remove it

Olds Scott

Sounds like the spring is missing. If you clean it up and lubricate like I mentioned than you need to get a new spring. Stock exhaust works better with this part installed