Just bought everything for 3.73 gears

While the GER performed okay, it was a poorly machined piece of crap that would crack a flexplate about every year. Replaced it with a 9.5 Dynamic that was built for the car.

Click to expand...

GER was the worst converter company on the face of the earth.



I've always used this RPM calculator, it's very simple and accurate.
https://www.ringpinion.com/Calculators/Calc_RPM.aspx

Original poster, what motor are you running?
I've read alot of threads about highway gearing and have one of my own and for the most part they're just a pee'ing match since it's all about personal preference. Some guys are fine with roaring down the highway at 3800 RPM's. I am not ok with that as it just simply annoys me.

My Duster has a 500" big block with a 727, 9.5" Dynamic converter, and an 8.75 with 3.55 gears along with rear tires that are 27.5" tall. I'm at 2800 RPM's at 65mph, yesterday I installed 3.23 gears which should bring it down to around 2400 RPM's.
When I have the energy, hopefully soon, I want to pull the 9.5" Dynamic and sell it or trade it for a tighter 10" converter. I drive my car alot and the motor has so much torque that the 3.55 gears feel like 4.10's so I'm thinking I'm gonna like the 3.23's.