Want to replace 4:10's with 3:55's

[EbodyPro572]

Since I am going with a 572 aluminum Hemi (by Tim Banning, FHO Hemi's) in my 73 Challenger, I want to change out my 4:10's with probably 3:55's or so.  Any suggestions on this or should i even go to 3:23's?  The car will have a ton of torque.  Any suggestions of brand/vendor, etc.?  Thanks, Scott

[Katfish]

3.55 should be a good choice.  I went from 3.55 to 3.73 and very happy.  All depends on what kind of driving you do.

Either way, Dr Diff is great.

http://www.doctordiff.com/

[Moparal]

So you have an 8 3/4 rear end?  With the 572 did you consider dana 60?  I went from 354 dana to installing 410's Im happy with the throttle response but busy at the shifter...which is fun to   I see katfish installed 373/s  I just got a set that size for my dana too, i'm wanting to try out. Might be better for rpm cruising with a 27.5 tall tire.

355's will be a good cruising gear for you, but 410's are a blast and if you can hang around 3500 rpms, then no problems either. But your cooling system works a little more

[Ck[FIN]]

I would say that the 3.23 gears would be very nice also. I have driven a 468cid chevy with lots of torque, it had 2.73 gears. It runs like hell and has absolutely no traction with street tires. And awesome to cruise with 1800rpm 

[422STROKER]

If you are going to drive more than race, then the 3.23's or even some 2.94's.

I got a little Stroker and 3.23's and plenty of fun with low traction from a start.

Tom

[moparmaniac59]

I am running 3:91 gears (8 3/4 rear) with a 543 cid stroker and like Al says, a bit of shifting, but OK. It's about 2900 rpm at 60 mph with 295-50-15's. Not too good on gas, but for the most part the longest cruises I do are about an hour or so. I think 3:55's are a good choice! With a 572, I would think you'd want a Dana 60. My 543 puts out 651 ft/lbs of torque. Enough to tear up my 8 3/4. I would think you might have even more torque. I am currently trying to score a Dana 60 myself. Good luck with the project!!

                                                  Matt B.

[Chryco Psycho]

I do not believe the 3.23 gears are available new so you would need a good used set

[Ck[FIN]]

If you have 489 case, here is a set for you

http://chucker54.stores.yahoo.net/choem8489car.html