The best idea is to make sure your leads are in proper plug-lead separators... this is good practice anyway, especially on a vehicle which will be subjected to wet mud in the engine bay.
If the leads are in good condition, then they shouldn't cross-arc, if they are properly separated, the risk is further reduced.
Most V8s have clips for the leads on the side of the rocker covers, and provided you keep everything tidy, then you ought to be OK.