heres an extract and link which describes whats needed .
"E-TEC engines require the open gap of a sparkplug to face or to be within about 90° on either side of the injector tip for best drivability.
The following link shows which plugs to use and how to identify 1998-99 FICHT heads, and the second part shows the tools needed and the indexing procedure.
Even though the E-TEC is not mentioned in the article, the indexing is performed the same way."
and the link is
there also a load of other info on the main "setup site"
hope it helps