Questions about exhaust manifold bolts and oil dipstick tube

[71CHEVYSHORTBED402]

71 C-10 402


Based on truck history, I'd have guessed these or most would be the original exhaust manifold bolts. Perhaps they are, but what a hodge podge. Some grade 5 & some grade 8. One is grade 2, which I bet we added when the A/C was pulled long ago.

Are the exhaust manifold bolts "supposed" to be grade 5 or 8? I'd guess 5.............................. On a side, Classic industry sells "original reproduction flange head bolts" for the exhaust. Not that I have much experience, but neither of my trucks have flange bolts. They're just a hex head and use lock washers.


The dip stick tube I pulled didn't have an O-ring, are they supposed to? From what I see there wasn't a leak.

Thank you.