3.23s Swap

[67valiant 100]

picked up a 3.23 geared 742 case for $50 bucks at Carlisle :yaayy: this weekend to replace the constant overdrive like 2.76s in the convertible. Has anyone else done this swap? How'd they like the gear ratio change? Figured I can rebuild the 489 case thats coming out with some track friendly 4.10 spool for the other cars.

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[tallhair]

Going from 2.76 to 3.23 will result in a definite seat of the pants feel and increase in acceleration. If the goal is quicker pick up w/o going to low while still keeping the RPMs under control at hwy or interstate speed then it's a good swap.

 

[1978 NYB]

Nice find...

Don't forget the speedo is going to be way off. You're going to need a new speedo txsm plastic gear to correct the speed.

 

[65sporty]

Are the u-joints the same size between the 742 case and the 489? I know the spline count is different on the yoke

 

[Wollfen]

Are the u-joints the same size between the 742 case and the 489? I know the spline count is different on the yoke

It depends on the options/motor, I have two dodge chargers and the 383 car has smaller width yoke than the other car which has a 440. so while the drive shafts are the same length for the same gearbox and such they are not interchangeable.

 

[62dodge]

Howdy NAPA has the U-joint for offset yokes the part number is NAPA 347 I've used this U-joint many times

 

[tallhair]

Me too. Not ideal I probably but have used them several times when swapping rears.

 

[1hotplymouth]

easy swap and speedo input is adjustable on side of tranns

 

[bluefury361]

I swapped a 3:23 sure grip into my 69 300, replacing the 2:92. Big improvement. Gas mileage suffered just a little. I found a speedo pinion gear on ebay, I think it is a 21 tooth "green". There are charts in the parts book you can reference for that. U joint was a direct fit.

The 3:23 has been my favorite all around ratio for several 440 auto cars I have owned, both B & C bodys.

 

[bulldogchesty]

I also changed mine from 2:76 to 3:23 and love it.