Whats everyone running for gears?

What are you running for rear gears

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4.10 SG w/28" tire. Bought a new 70 duster 340 w/ 3.91 SG, 833, and E70 14's (24.5 dia?). Drove it 15 years and 200,00 miles with only a valve job.Had two trips from MN to CO and about 50 runs down the strip (6000 sp). Reduced engine life???
 
I run 3:23's right now but when I had the 340 in it I had 4:56'S and the 4 spd. I just want to cruise now and need the 318 to live for a while. When it was new I had commando 273 with 3:23's and a 4spd and loved the combo for the street. I've got a o/d trans waiting to go in and I guess I'll be looking for a set of 3:55's for that.
 
I originally posted 3.91 in my Dart but opted instead for a set of 3.23 I had as well.
We like to take lots of weekend getaways and when I calculated that the Dart on 24.5 inch tires with the 3.91 at 75 mph on the interstate would be around 4000 rpm, I changed them to 3.23's.
 
I drove my '67 up to fresno to get painted, cruised around 3800-4000 rpm for 5 1/2-6 hrs
3.73 gears 25.5 tires
Ran like a top till I stuck 87 octane in it, too hot a plug tested that 87 and I had brown specs on the ceramic of the plugs, couldn't feel it though.... need a colder plug for that crummy octane or need to take the timing back 2-4*

Back up gears are 3.23's
 
shadango said:
2.76s in my 72 fish/ 318/727 right now.....looking for 3.55s in a 742 case with SG.
Click to expand...

An update for me: Just installed a 489 nodular iron case on my 8 3/4" with 3.55s and a Detroit Trutrack unit.

Its a 318, 727 , with 15.25" tires right now.

I am loving it around town so far.....its really odd revving so high after having the 2.76s in there....plus having other cars that have OD.

At 60 mph, I am running at 3,000 rpms.....at 65, 3,500 rpms. Seems kinda scary....LOL...I keep waiting for the engine to go "kaboom".....just not used to the higher rpms.

At 50, about 2,600.

I plan on some 275x60x15 tires (28" tall) to knock down the RPMs just a hair and fill the wheel wells better. Wondering what that will do as far as performance..,.am I taking a step backwards?
 
66cuda said:
Er ahhh this is kinda like comparing Apples to Zeppelins....kinda need to include what you are doing with the car/gears you are running...... street/strip 355, 373, 391, 410 Strip only 410 & up........ some guys dont mind revving 3500/4000 + on the highway....to me that spells short engine life....if your doing that 1/4 mile at a time...no biggy....if you're driving 100 miles to a show....budget for a new engine in a year or three.
I am more of a park & shine guy with the occasional wild *** hole shot. a good all around set is 355 or 373 391 jump like a bunny as do 410's but plan on visiting the pump a bit more often and taking your time to get somewhere.....
just my humble opinion
Click to expand...

Engine built correctly, rpm won't wear it out.
 
Original 3.23 open right now. I may change to a 3.91 sure grip someday. Right now it will blow the right rear off it with the 416 and it is still a blast on the highway. I don't bring this car to the track so I have fun with this as is right now.
 
Relax360 said:
running 4.11 with a gears vendors unit so I have 4.11 on the track and in OD 3.23 on the street
Click to expand...

How do you like the gear vendor unit? Any issues with it? Was thinking about this for my car.
 
Was using 3.23's for a while and decided to borrow a buddy's 3.91's for a while and NO, I don't wanna give them back.

I was cruising at 2200 rpm at 65 mph with the 3.23's but with the 3.91's I'm around 2800 rpms at 65 MPH. not bad but I can feel the difference and it took a bit bit getting used to the higher revs everywhere I went but it really woke the car up and the engine seems to love the higher rpms since I have a big cam and a single plane, but it's really hard to keep from putting my foot in the throttle.
 
shadango said:
2.76s in my 72 fish/ 318/727 right now.....looking for 3.55s in a 742 case with SG.
Click to expand...

To update mine --

I just got 3.55s (US Gears) in a nodular 489 case .....same 727 with a TCI Breakaway stall converter and tweaked 318. 25" (235x60x15) tires right now and wondering if I went to 275/60/15 if that would be too much tire for my combo.....like taking a step backwards???
 
I'm running some street friendly 4.56 gears until I get the 5.38 gears fixed. One of the spider gears in the sure grip bit the dust and the clutches are worn out. Dr. Diff is fixing me up with the parts.... just gotta pay the man. Then I'll get some new 28x13.5x15 Mickey Thompson ET Street tires and head out to the track and maybe, finally, get to see what it'll run. :burnout:


Wylde1.
 
4:10's here with a 727 and 28" tire... should be a monster on the street!
 
489 Case, 3.96 Gears, Sure Grip Posi Trac Clutch Style, Race Axle's
 
Acording to the gear calculator, I have a 4.11:1... No wonder my gas mileage sucks...
 
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