Yeah there’s a way to go 12X… I just did it
You need this 12X SBC kit and one of the brackets I had made.
https://www.holley.com/products/parts/556-171
If you happen to have a spare MSD Pontiac specific crank trigger, you can use just the mounting bracket with the 12X kit I posted above. Holley/MSD will not sell the bracket separately.
https://www.holley.com/products/igni...its/parts/8650
