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is 4.56's too much for me? #689303
05/05/10 08:57 AM
05/05/10 08:57 AM
Joined: Jul 2007
Posts: 150
South Carolina, United States
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carolinacuda Offline OP
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South Carolina, United States
Hey fellas. I was thinking of using my 4.56 gears which have been sitting on shelf for several yrs now. My 74 cuda with a mild 440 has 3.91's in it now. I have a 3600 stall and run a hughes solid cam 252/256 @50 with 572.579 lift ,108lsa. Indy Ez's with Eddy victor Int. My 60 ft is around 1.60 and my eigth is 7.25 and 1/4 of 11.48 at 117. I shift at 6200 and cross line at about 6000. Im using a 28'tire. I figured those 4.56's were too much with that tire. Not sure what to do yet. I mostly drive on street (city drivin though)

Re: is 4.56's too much for me? [Re: carolinacuda] #689304
05/05/10 09:05 AM
05/05/10 09:05 AM
Joined: Feb 2007
Posts: 970
Backwater, PA
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bwdst6 Offline
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Ah yes, nothing like driving a performance vehicle on the highway at 50mph getting passed by a Toyota Prius!


This post is available in double vision where drunk.
Re: is 4.56's too much for me? [Re: carolinacuda] #689305
05/05/10 09:11 AM
05/05/10 09:11 AM
Joined: Oct 2004
Posts: 8,165
Left Coast
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BobR Offline
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Quote:

Hey fellas. I was thinking of using my 4.56 gears which have been sitting on shelf for several yrs now. My 74 cuda with a mild 440 has 3.91's in it now. I have a 3600 stall and run a hughes solid cam 252/256 @50 with 572.579 lift ,108lsa. Indy Ez's with Eddy victor Int. My 60 ft is around 1.60 and my eigth is 7.25 and 1/4 of 11.48 at 117. I shift at 6200 and cross line at about 6000. Im using a 28'tire. I figured those 4.56's were too much with that tire. Not sure what to do yet. I mostly drive on street (city drivin though)




Too tall for the street and probably marginal for the strip.

Re: is 4.56's too much for me? [Re: carolinacuda] #689306
05/05/10 09:58 AM
05/05/10 09:58 AM
Joined: Apr 2009
Posts: 447
NJ
JCCuda Offline
mopar
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NJ
Back in the early 80's I went from 3.91 to 4.56 gears in my 71 Cuda. It was a 440, 10.9 compression with mildly ported 915 heads a Crane hydraulic 528/552 and I think 246/252 @ .050. It had a Torker with a vac.780 and a 727 with a Select Performance 3500 stall 10" converter. If I remember correctly the car picked up about 2 tenths with the gear change. It was all steel with full interior(see pic.). I was shifting at it 6,400-6,500 and I think going through at about 6,800. Best ET/MPH at that time was 11.72/117. Tire was 11.5x28.5x15. It drove good around town but you couldn't really do much highway driving. If you don't do to much highway driving with it I think I would give them a shot. Shifting that thing higher and going through higher has to be worth a couple tenths with your combo.

Re: is 4.56's too much for me? [Re: carolinacuda] #689307
05/05/10 10:18 AM
05/05/10 10:18 AM
Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
dave571 Offline
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Carstairs, Alberta, Canada
Crossing the line at 6k now with the 391's. it seems to me you are optimized now.

456 may even slow you down

Re: is 4.56's too much for me? [Re: dave571] #689308
05/05/10 12:00 PM
05/05/10 12:00 PM
Joined: Apr 2009
Posts: 447
NJ
JCCuda Offline
mopar
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NJ
With Indy EZ heads a Victor intake and a cam that's 252/256 @.050 there is no way that thing is done at 6000 RPM. That combo optimally should be going through the traps at around 6,500-6,800 RPM.

Re: is 4.56's too much for me? [Re: carolinacuda] #689309
05/05/10 12:08 PM
05/05/10 12:08 PM
Joined: Apr 2007
Posts: 2,026
Trumbull,CT.
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jim sciortino Offline
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Quote:

Hey fellas. I was thinking of using my 4.56 gears which have been sitting on shelf for several yrs now. My 74 cuda with a mild 440 has 3.91's in it now. I have a 3600 stall and run a hughes solid cam 252/256 @50 with 572.579 lift ,108lsa. Indy Ez's with Eddy victor Int. My 60 ft is around 1.60 and my eigth is 7.25 and 1/4 of 11.48 at 117. I shift at 6200 and cross line at about 6000. Im using a 28'tire. I figured those 4.56's were too much with that tire. Not sure what to do yet. I mostly drive on street (city drivin though)


Most cars do not see there best ET with a shift point higher then cross rpm.


The only way to find out is try them and different shift/cross rpms.

Re: is 4.56's too much for me? [Re: carolinacuda] #689310
05/05/10 12:12 PM
05/05/10 12:12 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
I Win
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Bend,OR USA
Quote:

Hey fellas. I was thinking of using my 4.56 gears which have been sitting on shelf for several yrs now. My 74 cuda with a mild 440 has 3.91's in it now. I have a 3600 stall and run a hughes solid cam 252/256 @50 with 572.579 lift ,108lsa. Indy Ez's with Eddy victor Int. My 60 ft is around 1.60 and my eigth is 7.25 and 1/4 of 11.48 at 117. I shift at 6200 and cross line at about 6000. Im using a 28'tire. I figured those 4.56's were too much with that tire. Not sure what to do yet. I mostly drive on street (city drivin though)


You got the third member, if you know (?)how to switch them make the change and let us know what you think afterwards


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: is 4.56's too much for me? [Re: carolinacuda] #689311
05/05/10 12:23 PM
05/05/10 12:23 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
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Romeo MI
Look at your gear change as a percentage and then
figure that percentage change in your rpm(I dont see
it being a problem) but if you spin the tires you arent
gaining anything... JMO

Re: is 4.56's too much for me? [Re: MR_P_BODY] #689312
05/05/10 02:43 PM
05/05/10 02:43 PM
Joined: Jan 2003
Posts: 9,146
Now - Port Orange,Fla. Former...
MIKES_DUSTER Offline
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Now - Port Orange,Fla. Former...
My uncles has a 68 RR with a mild 440,.509 hyd cam,10:1,mild heads,3800 converter,28x14.5 QTP's with 4.56.
It goes low 11's,shift around 6400-6500 and cross the same.
RUN'EM!!!!!!

Re: is 4.56's too much for me? [Re: MIKES_DUSTER] #689313
05/05/10 07:48 PM
05/05/10 07:48 PM
Joined: Jun 2009
Posts: 429
Sherman Texas
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The Shocker Offline
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Sherman Texas
I have 2 center sections for my Dart dragcar.One has 4.10's and the other has 4.86's in it.My car has a best of 11.48 in the 1/4 and 7.27 in the 1/8 with the 4.10's with the mild small block .With the 4.86's its crossing the line in the 1/8 at 6200 rpm and with the 4.10's its crossing at 4900 in the 1/8.It runs a better 60' with the 4.86's (1.57-1.58) ,but costs me a bit in the lights .With the 4.10's it will 60' around 1.60 or 1.61 .Believe it or not it runs exactly the same ET with either gear in it in the 1/8,but its easier to get it to leave and proly easier on parts with the 4.86's in the 1/8 anyway.I gain a bit off the line but give it back on the other end.BTW the 4.86's are useless for the 1/4 in my application thats why im hanging on the 4.10's for the 1/4 races .Confused yet ???..


http://www.youtube.com/watch?v=ykcsXMV3vfg My Dart ,and im just getting started...
383man [Re: carolinacuda] #689314
05/06/10 02:06 AM
05/06/10 02:06 AM
Joined: Jan 2003
Posts: 27,421
Balt. Md
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383man Offline
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Balt. Md
Quote:

Hey fellas. I was thinking of using my 4.56 gears which have been sitting on shelf for several yrs now. My 74 cuda with a mild 440 has 3.91's in it now. I have a 3600 stall and run a hughes solid cam 252/256 @50 with 572.579 lift ,108lsa. Indy Ez's with Eddy victor Int. My 60 ft is around 1.60 and my eigth is 7.25 and 1/4 of 11.48 at 117. I shift at 6200 and cross line at about 6000. Im using a 28'tire. I figured those 4.56's were too much with that tire. Not sure what to do yet. I mostly drive on street (city drivin though)





Wow my 63 would be a good race with your Cuda as my best is 11.49. I can tell you I use 906 heads I did some porting on. I run 4.30's with a 30" radial Hoosier slick. I drive on the street all the time like that. I shift about 6200 and hit the stripe about 6400 and I have the MP .557 solid cam. 4.56's with a 28" tire will be twisting your 440 pretty good for the combo. But you do have Indy EZ heads and a Victor intake (I use the Holley SD) so it may handle it. I am thinking if you shift about 6400 you should trap around 6600 maybe ??? Good luck , Ron

Re: 383man [Re: 383man] #689315
05/06/10 02:19 AM
05/06/10 02:19 AM
Joined: Nov 2004
Posts: 2,825
Sk. Canada
RemCharger Offline
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I'd say it might come down to a maximum of 1-1/2 - 2 tenths. Is it worth it considering your city driving... maybe not.
Would I put them in? Absolutely.

Re: is 4.56's too much for me? [Re: carolinacuda] #689316
05/06/10 06:58 AM
05/06/10 06:58 AM
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem Offline
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Ontario, Canada
Well first I get a shift point for that engine of 7000 to 7200. try 6800 and work your way up!! those heads really like it up high. you not giving that intake and those heads a chance to show their stuff.
I ran 4.56 on the street with 4.56 gears fine if you don't cruise the highway too much 4000 rpm is 72 mph with 28 inch tall tires. Thes motors will cruise all day at 4000.
2 to 3 tenths for the 4.56 (likely 3 tenths quarter and .2 in the 1/8) shifting it a 7000 will likely net .2 to .3 more ?? but with a 28 inch tire look for high 10's but 7000 out the end.
Perfect for your motor would be 29.5 slicks with the 4.56 or 4.30 gear and 28 inch tall either would still give 11.00's at 6800 out the end

Last edited by Dodgem; 05/06/10 07:00 AM.
Re: is 4.56's too much for me? [Re: carolinacuda] #689317
05/06/10 07:07 AM
05/06/10 07:07 AM
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem Offline
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Ontario, Canada
Where did you degree that cam in 106. the first thing I would do if you sticking with that tight converter is advance it to 102 and move the shift points up to 6800 minimum and i'll bet you find you 10.999's just with that.

Re: is 4.56's too much for me? [Re: Dodgem] #689318
05/06/10 08:33 AM
05/06/10 08:33 AM
Joined: Jul 2007
Posts: 150
South Carolina, United States
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carolinacuda Offline OP
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South Carolina, United States
Thanks for your responses guys. Yea i've been debating on raising shift points. Just didnt want to push her too much. I think i will try these gears and and raise shift rpms and see what happens. I guess i can always go back to what i got.







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