Ok, i've been using Denso Iradium spark plugs on my tibby, but since i've turboed i've notied a difference the way my spark plug is performing...probly because its a "stock heat class" (5) spark plug...i wanted a colder plug and it was listed on the site to use NGK (part number #BKR7E-11) as its a 2 step colder spark plug..that may be cold enough to keep you daily driving, and since its only $3 a plug thats pretty good, BUT for anyone else that wants the "ultimate" spark plug for out vehicles, (after some double and triple checking) i've found NGK RACING plugs that will fit our tibs (based on the NGK spark plug chart found HERE ) part number #R7116-9...its made of a different material and construction, and is 4 setps colder or R7116-10 which is 5 steps colder...only drawback is that they are also $22.34 each, but if any of you 375+HP guys are looking for a little more edge and steadiness out of ur tib...this MIGHT be the way to go....


AND for anyone that wants to understand what the spark plug number means use this chart to break it down Spark Plug 411 stock spark plug number from NGK is #BKR5E-11

 

use NGK BKR7E and gap them at 0.035"
we use similar plug on DSM and it's good enough to run low 10's.....