Overview Reviews Product Description 556-109 Holley EFI 8 ½” Crank Trigger Wheel 8 1/2" crank trigger wheel. Bolt hole pattern machinedfor SB/BB Chevy Engines Product Videos Custom Field Product Reviews Write a Review Write a Review × 556-109 Holley EFI 8 ½” Crank Trigger Wheel Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *