As I reassemble my " Disco in a box" I find that the PO lost the Exhaust manifold bolts and the Trans bell housing to engine bolts. They both appear to be 3/8" coarse thread, do they need to be grade 5 or will hardware store bolts work. Torque values don't appear to be too high. Any Ideas Thanks Folks!

 

Go with grade 5 on bell housing and grade 8 on manifold. 33 ft/lbs isn't a whole lot but look at what they're holding so grade 5 is fine on the bell housing. Grade 8 on the manifolds is a personal preference because they're heat treated - handle high heat well. I use them on all my low pressure steam line connections at work not for clamping force but heat handling and reusability which is the key here.

 

Thanks Ihscout, hadn't thought about the heat treated part.