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#2413734 - 12/05/17 04:00 PM Rearend gear selection help needed.
galen Offline
super stock

Registered: 05/02/09
Posts: 754
Loc: Missouri
This is mainly a cruise night type car that will be making a few 100 plus mile trips for shows, etc. 68 Plymouth Satellite. Engine is a 588, Koleno block, 572-13 heads. Peak torque 817 at 6200. Redline 7000rpm. Tires are M&H 325/45/17 drag radials 28" diam. I am a paraplegic and drive with hand throttle and brake. In turn I opted for a fully programmable TCI 6X with upgrades. Gear ratios are 2.97,2.23,1.57,1.18,1.00,0.75. 3600 stall. I am leaning toward a 3.73 in a Strange S60. I want acceleration more than top end. It is a heavy all steel car, AC etc. I value your opinions. Thanks, Galen

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#2413739 - 12/05/17 04:09 PM Re: Rearend gear selection help needed. [Re: galen]
6bblFLASH Offline
master

Registered: 01/20/03
Posts: 3530
Loc: N.E. Ohio
Even a 3.54 would be plenty,Thats a healthy engine!!
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70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas 9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ! 2013 StickShift Challenge Winner@ Mopar Nationals!

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#2413751 - 12/05/17 04:21 PM Re: Rearend gear selection help needed. [Re: 6bblFLASH]
fourgearsavoy Offline


Registered: 12/07/04
Posts: 9252
Loc: Rittman Ohio
Yeah with that 2.97 first gear a 3.54 will be plenty. I had a 3.27 low gear in my Richmond and 3.54 gears in the rear and it came out of the hole quite nicely thumbs

Gus beer


Edited by fourgearsavoy (12/05/17 04:21 PM)
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64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60

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#2413752 - 12/05/17 04:22 PM Re: Rearend gear selection help needed. [Re: fourgearsavoy]
an8sec70cuda Offline
I Live Here

Registered: 01/19/03
Posts: 10665
Loc: Marion, South Carolina [><]
iagree With that first gear ratio and a 28" tall tire, I'd go w/ 3.54s.
_________________________
CHIP
'70 hemicuda...8.91 at 150.5 mph street car...Mopar Action feature Dec. '14
'69 road runner 446" w/ Indy SRs
'69 road runner 440-6, 4 speed...Dad's ride
'71 Demon 340 resto project
'01 Ram 2500 QCSB 4x4 Cummins...toy hauler
'16 Grand Caravan SXT...baby hauler

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#2413801 - 12/05/17 05:28 PM Re: Rearend gear selection help needed. [Re: galen]
dvw Offline
master

Registered: 03/16/06
Posts: 6994
Loc: MI, usa
Even a 3.54 has more starting line ratio than a dedicated drag car needs at this power level. Definitely doesn't need any more than this. My 9.0 drag car 2.45x4.30=10.54 (too much) with 10.5wx31, for comparison 2.97x3.54=10.51 on a 28" which are 10% shorter
Doug

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#2413840 - 12/05/17 06:44 PM Re: Rearend gear selection help needed. [Re: galen]
CMcAllister Offline
top fuel

Registered: 12/30/05
Posts: 2359
Loc: Fulton County, PA
3.73 or even a 3.54 with those gear ratios? It's going to be a tire baking machine. Honestly, if you could eliminate using the 2.97 and just use 2.23 as low gear, it would work much nicer I think. Then maybe the 3.73 is manageable. 3.73x2.23=8.32 And with the overdrive, it will be OK on the highway.

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#2414162 - 12/06/17 10:29 AM Re: Rearend gear selection help needed. [Re: galen]
an8sec70cuda Offline
I Live Here

Registered: 01/19/03
Posts: 10665
Loc: Marion, South Carolina [><]
dvw...I agree that even a 3.54 w/ his 1st gear is too much SLR for his motor, but (as you know) the 3.54 is the lowest numerically commonly available gearset for the Dana. If he could find a taller gear, not sure what Strange has for them, that'd definitely be better.
The car is set up more like a street cruiser even though it has a serious motor, so the 3.54 will likely be fine for him. It'll be like driving on ice from a dig though w/ that SLR and 17" drag radials on the street.
_________________________
CHIP
'70 hemicuda...8.91 at 150.5 mph street car...Mopar Action feature Dec. '14
'69 road runner 446" w/ Indy SRs
'69 road runner 440-6, 4 speed...Dad's ride
'71 Demon 340 resto project
'01 Ram 2500 QCSB 4x4 Cummins...toy hauler
'16 Grand Caravan SXT...baby hauler

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#2414256 - 12/06/17 01:06 PM Re: Rearend gear selection help needed. [Re: galen]
Cab_Burge Offline
I Win

Registered: 08/23/03
Posts: 30946
Loc: Bend,OR USA
First of all on a street car with that much power and torque along with a trans that you could start out in second gear I would not use radial tires of any sort on that combination on your car tsk twocents
I've had a lot of race cars and Hi Po street cars(both 4 speeds and automatics trannys) with a lot of different sizes, brands and types of rear tires, the radials on a good track are faster and better, not so on the street shock puke
I would buy another set of wheels and put the biggest size M.T. ET street tires(maybe even a set of Hoosiers scope confused) I could fit on the car for street use, you will have to let air out to make them wheelie on the street though devil boogie
Good luck, be safe and have fun up
As far as the rear gear ratio sit down with a calculator and do the math on each rear gear ratio along with the 1st and 2nd gear ratio in the tranny and then decide which starting line ratio you think you want for racing and maybe a 4.10 or a Dana 61 with 3.30 ratio will work scope shruggy
I've race a 4 speed car on the street and started out in second gear with a NP 833 non O.D. to limit the tire spinning whistling devil up
_________________________
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

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#2414574 - 12/07/17 01:04 AM Re: Rearend gear selection help needed. [Re: Cab_Burge]
galen Offline
super stock

Registered: 05/02/09
Posts: 754
Loc: Missouri
Thanks for the replies. 3.54 is about as high as I can go with the Dana 60. I have not bought my wheels and tires or ordered my rearend yet, but I am ready to do so.. On the front I can run a 16 inch wheel the smallest for the disc brake size I have. I am not locked into a 17 inch for the rear and could order my disc brake size accordingly. Car is mini tubbed to the rails and currently has a 3 inch relocation kit on it. I believe I can run up to a 29 1/2 inch tire without having to do anything to the outer wheel wells. As Cab brought up is there a better tire option that you would suggest? Bias ply, MT ET street or Hoosier. Car will not see wet weather. Thanks again. You guys have given me a lot to think about. Galen

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#2414612 - 12/07/17 08:31 AM Re: Rearend gear selection help needed. [Re: galen]
an8sec70cuda Offline
I Live Here

Registered: 01/19/03
Posts: 10665
Loc: Marion, South Carolina [><]
Pros and cons both ways on the tires. The drag radials drive a lot better, but won't hook nearly as good on the street as a bias ply tire. If you're concerned w/ traction, go w/ a bias ply tire but use a sticky one...like the Hoosier Quicktime Pro or M/T ET Street. Don't waste your time w/ a M/T sportsman or the normal quicktime tire. They are bias ply, but will handle like one AND not hook worth a damn.

If traction is your main concern, stick w/ a 15" rim.
_________________________
CHIP
'70 hemicuda...8.91 at 150.5 mph street car...Mopar Action feature Dec. '14
'69 road runner 446" w/ Indy SRs
'69 road runner 440-6, 4 speed...Dad's ride
'71 Demon 340 resto project
'01 Ram 2500 QCSB 4x4 Cummins...toy hauler
'16 Grand Caravan SXT...baby hauler

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#2414641 - 12/07/17 09:39 AM Re: Rearend gear selection help needed. [Re: galen]
polyspheric Offline
master

Registered: 10/10/07
Posts: 2668
Loc: New York
What does your converter manufacturer say is your minimum cruise RPM for acceptable converter slip?
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