M809: Exhaust header to muffler bolt size/grade

[MyothersanM1]

I am going to be pulling out my muffler to do some welding repairs. The header to muffler inlet flange bolts appear to rusted pretty good. Does anyone know size and particularly the grade of bolts used to fastened the two parts together?

Thanks in advance.

 

[rmgill]

I think they're 1/2". You'll want stainless if you can get them. They'll handle the temperature changes better and not seize.