Just ordered a new set of plugs and plug wires from internet web site.
Does the gap still need to be set/checked on new plugs? If so, can someone
advise what the gap should be for a 1992 300E 3.0L straight-6?

Thanks!

 

Yes. Check the gap before installing. The gap will most likely be incorrect since the plug fits more than just your engine.

If you have an owner's manual, the proper gap can be found in it. If not, call a local auto parts store and ask them.

 

not unless you write down the sparkplug number that we can advise the gap.

0.8mm is okay.
1.0mm is okay too.

 

Does this help?

http://catalog.eautopartscatalog.com...art=Spark+Plug

Sorry for the large "link".