Moroso Spark Plug Indexing Washers

High-compression race engines require “indexing” of spark plugs to prevent contact between the piston dome and ground wire of the spark plugs.

Moroso 62160 Spark Plug Washer Indexing Nut Indexer Tool, 14mm

Spark Plug Indexing Washers - Thunder Products Carburetion Performance

NGK Spark Plugs NGKTR5 - NGK Spark Plug 8-Pack

indexing plug ground electrodes

B&B 30500: Spark Plug Index Washers For 14mm Tapered Seat Plugs W/ 5/8 Hex - JEGS

Moroso Mor Washers 71910 — ROCO 4X4

Moroso Indexing Washers 5/8 Taper

Help with plug indexing please - Barnacle Bill's Marine Supply

Help with plug indexing please - Barnacle Bill's Marine Supply