If you are talking about the intake to head bolts, no. The exhaust studs will break however, and you have to take off the exhaust to replace the gasket. Soak them down with WD-40 and keep your fingers crossed. Replace any bad studs while everything is apart.
greg 71 240z
Nearly every bolt that I touch on my '78 seems to be fused with 21 years worth of corrosion, and consequently approximately half break. I wouldn't know what to do without WD-40 (or equal penetrating oil). It helps for sure. Be prepared and soak'em over night and again before working on them. They still might break, but its not the end of the world. Just continue to remove the parts. When the manifolds out of the way the broken ones will be easier to remove. Vise grips work pretty good if the bolt snaped at the head. That's been my experience with most of'em. Good luck.