Nuts and Bolts

Typically the bolts used on cars are stronger, and frequently have special coatings. As long as you replace the bolts with ones that have the same strength ratings and coating (cad, zinc, etc) then you'll be alright. Another alternative is to take a couple of wrenches to the junkyard. Most of them will just give you the bolts, and while you're there you can stock up on bulbs and fuses.

JazzMan

Thanks, JazzMan, I guess it's about time I got to know my local junkyard any way.

Often for manifold-to-downpipe connections brass nuts are used. VW used copper nuts for some engines. Makes it much easier to remove stuff if necessary - if they're stuck you can burn 'em right off.

nate

Galvanize is just the coating that make them rust proof. The grade of the nut is more important. Look for grade 5 or 8. Your biggest problem is that the ones from hardware store are most likely not locking fasteners. Factory nuts and bolts usually have a deformed thread on the nut or bolt to keep it from coming loose. If you just put a free running fastener on the exhaust manifold, chances are it will come loose quite quickly. Mine started coming loose in less than 15 minutes. If they come loose, your manifold will warp or worst, crack. The baseline is you should always use new OEM nuts for exhaust manifold. Don't use nylon locking nuts since it will melt. Don't use split washer either, they will eventually come loose. If you can find deformed locking nuts at the hardware store, then great. Otherwise, if you must use nuts from hardware store, get some Nord-lock waher from McMaster-Carr. They are really good, and are cheap. For all out security, use Stage-8 reuseable fasteners. See:

differently