what rear end gears?

[68MoparCharger]

What rear end gears should I go with for a strange engineering strange 60 with detroit locker, I am going to have a 730 hp motor with 660 ft lbs tq, the cam is rated for 4000rpm to 7000rpm, 727 torqueflight with gearvendors over/underdrive with 4000 stall converter, and normal street tires will be 285/40 r18 pirelli pzero nero m+s tires on the back.  I'd like to know what gears would make sense for this application if I were to use it as a daily driver around town, a few times on the highway, and at the strip on the weekends with 29 x 12 slicks?  I personally was thinking something between 3.73 and 4.10.

[dodge freak]

That sounds more like a racing motor than a street motor. I would think 4.56 for that, don't forget the overdrive that knock it down so will the 29" tires. With that 4000 stall it still be slipping alot in overdrive unless you are going at least 100 mph. EX: 4.56 gears x.69 for overdrive =3.14 gears --Now take 3.14 x 336 x speed { 100 } = 105719.04 divide that by the tire size which is 29 that equals 3645 rpms. Make sure you have a big trans cooler for it and lots of gas in the tank, sounds like a 5 mpg car.

[Mike DC]

 
To tell you the truth, I think you've got a conflict-of-interest working here. 
You've basically rattled off a set of specs for a dedicated drag-racer motor, but I'm guessing that you're wanting the OD & gearing in order to make it more streetable? 

Just as a general comment, I don't see it working very well on the street.  Driveable but not great.  Certainly not much of a highway cruiser.

It sounds like it's gonna be fun as heck at 4000-7000 rpm and the track times are gonna be serious.   But at anything lower than 3500 rpm it's is gonna feel kinda mushy & sluggish (not to mention heating the heck out of the tranny fluid).   You can force that motor/tranny's rpms down with the OD & axle ratio but you can't make that motor actually like it.

 

[68MoparCharger]

The engine with this cam in it is a Indy Legend 528", it says for the cam you're supposed to have a 4000 stall converter. Because the engine is so large, could I go with a lower stall speed? 

[dodge freak]

Usually a 3000 stall is tops for a street motor, thats what I would get. If its not enough get a smaller cam for it. You need to drive it and see, a 4000 stall is only when you floor it but still thats pushing it to far for the street. Unless you live out where there's no traffic lights and 25-35 mph speed limits.

[Mike DC]

 
I agree.  Gotta bring the stall-speed and cam size down if this car is gonna see any street cruising.

Switching down the camshaft size may function to increase the compression somewhat.  Brings up fuel octane issues.

 

 

 

[Ghoste]

And as for gears, I agree about the tall tires and overdrive.  Throw the steeper gears in(4:10's at least)and have some fun.

[deputycrawford]

I agree with everybody else here. I have a 9 1/2 inch converter in my 69 and a 4:10 gear with 28" tires. I have a larger cam in a 383 and it needs to rev to feel good. You need to go smaller with the cam and the converter. Dynamic makes the 9 1/2 inch in the 3500 stall. I drive mine on the street all the time and it takes off from a light at around 2000 rpms at part throttle. Thats the max I will go on the street. You can go with much less cam and converter and still rip your neck off with a 528. Think smaller and you'll go faster.

[phat69charger]

What rear end gears should I go with for a strange engineering strange 60 with detroit locker, I am going to have a 730 hp motor with 660 ft lbs tq, the cam is rated for 4000rpm to 7000rpm, 727 torqueflight with gearvendors over/underdrive with 4000 stall converter, and normal street tires will be 285/40 r18 pirelli pzero nero m+s tires on the back.  I'd like to know what gears would make sense for this application if I were to use it as a daily driver around town, a few times on the highway, and at the strip on the weekends with 29 x 12 slicks?  I personally was thinking something between 3.73 and 4.10.

68MoparCharger you can use this calculator and plug in all of your own information and see for yourself what your Rpm's and Mph will be for your Charger
http://users.erols.com/dmapes/GEARCLC.HTM

Here's another post about gears if you haven't seen it yet: http://www.dodgecharger.com/forum/index.php/topic,17425.msg193541.html#msg193541

[NYCMille]

I am running the exact same rear tire combo - 285/40/18s - I have a mild 440, 727 also with a gear vendor OD. Currently I am running 3:55s and I love em'. You can cruise at 85mph all day long and spin about 2850rpm - then kick it out of OD and really take off - you could also run 4:10s but I wouldn't go any higher than that - one of the best parts of the 3:55s is that you can take the car up to 120+ or so then go back into od and keep pulling.... it's a great feeling.

[dodge freak]

I would love to get a gear vendor for my car, I allready have a 3.91 gear in back but not the $2000+ money for it. If you can afford it thats the way to go for sure.