Accel, U-groove spark plugs, one range colder - 48-74 B.T.(NU) 515014 - Machined from 6061-T6 billet

- Machined from 6061-T6 billet aluminum

Used with Andrews 07-17 style conversion cams only

today’s larger and more powerful engines can cause a lesser fastening system to come loose from large power pulses combined with the back and forth motion from getting on and off the throttle

Today less popular amongst mainstream riders but a still an up an kickin' favorite in the Retro scene

Accel, U-groove spark plugs, one range colder - 48-74 B.T.(NU) 515014 - Machined from 6061-T6 billetH D #3 4. 14mm threaded, short reach. Used with 21mm spark plug socket. Used in high performance or hard ridden engines in which standard heat range plugs become overheated.