Are you sure you want to do that? Have you driven one yet? We have TRACTION PROBLEMS even without the supercharger While STOCK Gearing lets you do stupid 199MPH (More if you disable the limiter with a tuner) 4.10's I think it would be impossible to get traction, even with slicks
An 8-71 aka 8X71 cubic inches blower would displace about 9.3 liters, IN THEORY. The usual Detroit 6-71 blower was for the 6-71 six cylinder Detroit Diesel 2-stroke which had 71 cubic inches in each of its six cylinders. The blower for the 8V92 would be something I'd like to see, too. I do not know if the 6-71 blower of fame actually HAD 426 cubic inches aka around 7 liters of displacement. Then there's the 16V149 Detroit which had twin blowers. Not all of the cylinders are fed by one monstrous supercharger.
There are rear end replacement kits that place a Ford 9 inch pumpkin in place of the stock rear differential, and with that, you would have a very wide variety of gear ratios from which to choose, including the 4.10, 4.56, etc. That is relatively unnecessary with the automatic Hellcats, as their first gear is so low that they have a 2.62:1 rear end ratio. The manual versions have a 3.70:1 ratio in the rear end because with so few gears (6) their first gear is not as low as the one on the automatic. with a 4.10, that final drive ratio on the manual would be a smidgeon closer to the phenomenal 12.23:1 of the automatic, at 9.266:1.
The AT Cat featured here has the 3.09 option installed in the factory diff. which makes a 1st gear launch even more restrictive than the 2.62 they replaced. Many with similar hp increases find benefit launching from 2nd (not necessarily for loss of traction). The Ford 9 inch are popular in large part due to their strength.
