71 Cuda 440 6pack Lacks raw speed

[Phantom]

Hello everyone.I am a new 71 Cuda owner.The car has the 440,6pack with the hemi 4speed and 355 rear.Everything is fresh and rebuilt and checks out.Car has 14inch wheels with f60 tires.The problem I am having is this car goes through the gears very quickly and just flat out runs out of gear at the top of 4th gear and doesn't have much top end speed at all.Car doesn't have a tach so not sure about what the RPMs are but it sounds and feels like it would be really easy to over turn this engine trans rear combo if you tried to wind it out.In comparison I have a stroked 383,4speed,323 rear 70 Roadrunner that has all the top end you want.Is the performance of this Cuda combo normal,or is it just me or do I have another problem.Thanks for any input on this in advance.

[HP_Cuda]

Sounds like you have 4.11 rear end gears.

Ever find out what they are?

[Phantom]

I am going to get the car on the lift tomorrow and turn driveshaft and count the revolutions of wheel and verify for sure.Something is off for sure.I have been told the setup in the car feels like it could use another gear.On the list is putting the hemi trans on the shelf and putting in one of Passons 4speed overdrive trans in it for more Highway speed.This my first Cuda so trying to check with long time owners if this is normal or not.

[67vertman]

I have a 70 440 6 Pac and I had a standard 4 speed and 4:10 gears.  You are correct they run through the gears and hit top RPM pretty quickly.  I went with the Passion 4sd OD and love it.  Now I can travel the highways and cruise at a comfortable RPM. 

Welcome to the board. 

[Phantom]

Thank you 67vertman.Are you running 14inch wheels?.Not really feeling the 14s that are on mine.15s like came on the AARs would help also.I like that stance and offset from front to rear too.I think thats the way I am heading.But to go along with that the rear of car will have to come up by way of tailer leaf springs from what I have gathered.Have to verify for sure.

[Phantom]

Once I get the gearing right I needed to sort out why the car vibrates with some whine through the tranny excessively.Coming through the shifter handle quite a bit.My Roadrunner has almost Zero through the shifter.

[67vertman]

Yes, I am running 15 inch rims with BFG 275 65R 15

As for the whining, it could be your throw out bearing, does the whining stop when you push the clutch in?

[1 Wild R/T]

18 spline "Hemi" boxes tend to have some gear noise do to the gear design... Not a pronounced as GM's "Rock Crusher" but noisy just the same...  And yes 4:10 gears tend to top out pretty quick, even 3:54's which is the more street friendly option in a Dana runs outta gear pretty early...  O/D is a good upgrade..

[Phantom]

I just put the car on lift and sure enough its a 4.11 rear not 3.54.That explains about lack of speed.Thanks  HP Cuda for pointing me to it sooner than I would have found it

[HP_Cuda]

 

Time for OD!!! or change out the gears.

[Phantom]

Isn't A33 code for Track pack 3.54 in 71

[rUNCHARGER]

The OD 4 speed will clear that right up. I find 3.54 isn't highway friendly either. 3.23 is about as low geared as I like them and that doesn't work with a Dana 60.

Sheldon

[Phantom]

If a Dana could take a 3.23 that would be the deal for sure.