While you can use an older oil-filled coil with the HEI, the newer, e-core coils (as shown) are more efficient and can be easily found in the junkyard. The coil with the bracket was off a late-’80s Chevy pickup. There’s also a ton of high-performance coils available from ACCEL, Crane, MSD, and others. Be sure to match the coil to an HEI inductive ignition. Do not mix coils intended for capacitive discharged (CD) ignitions with an inductive module. All factory coils are inductive and will work with an HEI.