I'm thinking the 3.64's out of a 4 speed auto car would be just about right for a kick out of the hole and still only be 2600 rpm at 70 mph. That makes it about the same in 5th overall as the stock 3.06 rear end with the trans. held in 4th, except for the extra dig getting going.
Hey 73 sixpak, There are so many answers to your question that to save you time and answer your next questions...go to LATEMODEL RESTORATION SUPPLY and look up challenger rear end gear change.They show you how to install the 3.55 gears in your rear. The Diablo programmer does NOT recogonize the 3.64 ratios..axles are also different between the various housings,Getrag,Mettingen 210mm-215mm good luck--Cfan
Well guys I just bought a spare rear end housing from a salvage yard.It's out of a 09 challenger--it has the three bolt pinion flange like MY housing. I decided not to spin the wheel of luck with a housing from a charger,300,or magnum and find out something isn't the same. I will be working on it to put the 3.55 gears in--then I'll have the option to run 3.06 or 3.55 by simply changing carriers.
Just curious but don't the new "drag pak" Challenger RT's come with 3.90 rear gearing? If so, wouldn't 3.90 be preferable to the 3.64's & 3.55's mentioned? Just R&R< right or is there a bit more involved in doing this swap?
Hey Doozle, The 3.90 gears come behind a 6 speed manual trans with a 3.00 first gear---the auto has a 3.58 first gear which means you'd be in first gear for about 7 feet--which would give you 4 more gears basically making the auto a 4speed auto--also the Diablo tuner will not let you tune that combination. Hope that helps--cfan
You're welcome Russell--I haven't installed the new 3.55 gear in the spare housing yet.I've been working on the engine compartment,but it is my next project. The Drag Strip here opens in about a month---my buddy has a 2010 camaro ss 6speed. We are going to race heads up---I will lose--but--I will have some REAL numbers to share from BOTH cars--not BLOG numbers--then when I install the gears we will see the REAL results. I may still lose,maybe not--but either way I will post the results. The times will seem slow due to the fact our track is at 5000 ft--but they will be real.My 1970 Cuda runs 11.90s here which may not seem that fast for a street car--but the corrected index for Super Street 10.90--is 11.56 here.