The engine is so big it has bolt patterns for either Chevy or Chrysler crank is drilled for hemi 8 bolt flywheel/flex plate. So transmission has options. I currently have a JW ultra power glide with Gear Vendor OD unit. It can easily handle the power. But heat will be a Pro for any "Street" type application. So still searching for options. Car does have setup for clutch pedal. They ran an A833 crashed boxed trans in the 70s behind an 800 HP 426 hemi.
