There are no specifications for this plug this is a racing plug for modified engines

Autolite AR3911 14mm Racing Spark Plug, 5/8 Hex-Gasket Seat, 3/4 Reach

Spark Plug Seat Style:
Gasket
Seat Taper:
Gasket
Spark Plug Reach:
0.75"
Thread Pitch:
14mm
Insulator Type:
Projected
Resistor:
No
Spark Plug Heat Range:
4
Core Material:
Copper
Tip Material:
Nickel Alloy
MFG. Part #:
AR3911
Overall Length:
14.00"
Wrench Size:
5/8"
Sold in Quantity:
Each