Hi Austin, you posted again! After your first post back in Aug 2022, when you didn't respond to anyone's answers about fenders, we thought you might have ghosted us. Nice to have you back.
You've definitely come to the right place here, I'm sure every one of us would also like to have a 1000 hp plus supercharged hemi in our cars. You'll have to slide some pictures over when you get yours!
If you're thinking of a modern automatic like the hellcat uses for your Charger, you'll have a couple of issues to get out of the way. First of all, heavy duty eight speed transmissions, like the ZF designed torqueflite8 are large units, you'll need to modify your transmission tunnel. And since they're using the small block pattern that the modern hemi engine has, you will also need an adaptor. Plus electronic controls to make it shift with your engine.
There are also six speed manual transmissions that you could use, but unless you have race track only tires (sticky slicks) you won't get all that power to the ground anyway so don't worry about breaking the transmission. A Getrag V160 would work for you, they were popular with the turbocharged lexus/Toyota six cylinder crowd with their 800-1200 hp. engines. And believe me, there are a LOT of Toyota Supras and Lexus SC300s out there that you'd never suspect had that much power. You could also opt for the six speed used in the last Vipers, the Tremec TR-6060. It's also used in the Cadillac CT5-V Blackwing, and won't be cheap but at least you can say you have a Cadillac tranny.
Why the need for so many gears anyway? You know when Dodge offers the drag race Challenger Drag Pak, they just put in a beefed up Turbo 400. I mean face it, if you just want acceleration, with the engine you're describing you could use a two speed automatic and still get it. You could also save yourself the hassle of modifying transmission tunnels and just buy a properly built up 727 and then put in an overdrive unit in front of the beefed up axle that you'll need for that much power.
