NGK BPR5ES Spark Plug Cast Iron Heads or Ally Heads - Big Block - EACH

The NGK BPR5ES Resistor Standard Spark Plug is designed for reliable ignition and optimal engine performance. Its premium design and construction enhances spark efficiency, delivering smoother starts, better fuel combustion, and consistent power across all driving conditions.

The NGK BPR5ES is more suitable for classic or modified big block engines than the NGK BP5S due to its correct thread reach, built-in resistor, and wider design availability. 

Key Differences Between the E v S plug:

The 'ES' designation means a 19 mm (3/4-inch) long reach thread, which matches standard aluminium and modern aftermarket big block cylinder heads. The 'S' in BP5S often denotes a short 9.5 mm (3/8-inch) reach meant for older, shallow-reach iron heads, which will leave exposed threads in a long-reach hole and cause carbon fouling or misfires.