Do the exhaust manifold bolts come out without issue? Or do they typically break?

Will typical grade 5 or grade 8 bolts work as replacement?

TIA
RS

 

Spray PB Blaster generously and they should be fine.

 

of the 3 Rovers I've had apart , all the exhaust bolts came out without much problem...except for the D2 I did which had apparrently been "loctited" extra at the factory....they needed to be heated just a little to soften the loctite so they would turn out
I replaced mine with grade 8..

 

Most of mine have come out ok, some have pulled out a coil of aluminum when they came out though. Odd ball metric thread size from what I can remember. I have trouble finding the correct thread pitch, unusually fine for the size of bolt? Think it was a 1.25mm pitch?

 

remember.....these heads are old Buick parts....all of the disco's I have worked on have standard sae threads 3/8"-16 for the exhaust bolts, I usually run a tap in all the bolt holes just to clean them up before re-installing the new bolts