Dave Gilbert said:
Iv got denso iridiums because I couldnt find ngk iridiums, they have been fine for about 6000 miles.
NGK Iridium IX for the GM L61:
LTR5IX-11 # 4344
Description - Iridium IX Plug, 14mm Thread Size, 25mm (.984") Reach, 5/8" (16mm) Hex Size, Tapered Seat, Resistor, Projected Tip, Solid Terminal Nut, Fine Wire (0.6mm) Iridium Center Electrode, Tapered Cut Ground Electrode, .043" (1.1mm) Gap, Heat Range 5
(LTR6IX-11 is 1 step colder / LTR7IX is 2 steps colder)
I could be talking a load of old 'nonsensby' though. 🙂