1991 Rolls Royce Rolls Royce Silver Spur "champion bosch spark plug cross" Questions

...craft spark plugs in 4.6l 24 valve v8 Almost all plug manufsctures cross reference plugs.. just look up your car on a chart for the manufacturer that you want to use.. such as champion, AC, Bosch

...Champion, Denso, NGK...all decent stuff)...and that is the PROPER DESIGN AND HEAT RANGE FOR THE ENGINE ITS GOING IN! Here is where it gets touchy, what Autolite calls a 155, may be what Delco calls a ...