Lots of supercharged 800-1000+ HP Hemis running FAST in heavy late model Dodge muscle cars and Jeep SRT 4WDs at 4500lbs.

Usually,past 800 WHP in heavy cars the trans needs a few mods, lots of 8 spd specialists around building them. They still use the OEM style torque management between shifts. I imagine this could be achieved with a programmable timing control unit to pull timing between shifts.

The software/electronics for the swap now exists and are sorted; adapters are available to allow it to bolt up to a BBM. If you have a modded trans tunnel and eliminated the torsion bars with a coil overs as I have the swap is way easier, but many are'nt willing to do that to their rides so that is the deal killer.

I've seen converters to 4500 rpm stall but if required, I have'nt seen anything with more stall available as yet.

I'm looking into possibly going down this path in the future. Changing out the gears in the Dana in my car to 3.23s with a 30" tire would be work and it'll be closer to a Hellcat's 3.07 rear gear option with the tire OD. With a 4.71 first gear you'll be ripping through the gears like a Hellcat hence the low number final drive ratio with a double OD in 7th and 8th to boot.

Info from the Hellcat forum:

1st -- 4.714
2nd -- 3.143
3rd -- 2.106
4th -- 1.667
5th -- 1.285
6th -- 1.000
7th -- 0.839
8th -- 0.667

Hellcat 2.62 final drive
( 1st x Final drive )
4.714 x 2.62 = 12.35068 SLR

(2nd gear x Final Drive )
3.143 x 2.62 = 8.23466


Old NAG1
( 1st x Final )
3.588 x 3.06 = 10.97928


727/904 with various gear ratios

( 1st x final drive )
2.45 x 4.10 = 10.045
2.45 x 4.56 = 11.172 ( Close to NAG1 )
2.45 x 4.88 = 11.956

4.88s and still not there yet SLR wise.

2.45 x 5.13 final drive = 12.5685


Hellcat vs Old School
To compare a 1st gear start - Your final drive ratio would be around 5.04 with a 28" tire
To compare a 2nd gear start - Your final drive ratio would be around 3.36 with a 28" tire


To complete the swap, you'd have to use an OEM style Hellcat shifter, aftermarket shifter handles are available to make it look like an aftermarket 3 spd shifter.

I think it would be awesome if I could get the appropriate converter sorted out.

Lots to consider, it ain't a straightforward swap but it can be done.