Race quality heavy duty double row performance timing chain. This is not an endless chain! It is the best chain available and used by top engine builders, also fits MGB/Midget. This chain is for duplex gears that is used by racers as a limited stretch heavy duty version made to stringent quality control to exact dimensions for perfect engine timing. See also our standard duplex gear kit C-AJJ3323. Lightened duplex kit C-AJJ3324 or steel lightweight.