3 speeds , lowish power and limited redline don't work well together.

Did the Wranger ever come with the 4 speed over drive automatic Torqueflight? If so, the conversion _will_ be worlds better to drive with 4 speeds and a lock up converter.
( Some Jeeps came with a Toyota automatic that I know little about )

OD and lock up on a Torqueflight are triggered by a solenoid for each. The OD bypass switch is usually on the dash so the shifter will look the same as a 3 speed.

Yout trans with 2.74:1 first, 1.54 second and 1.00 third has the wide ratio gear set where older stuff had 2.45 1.45 1.00 . OD is somewhere around 0.69 and I'm not sure if the wide ratio 1 and 2 were used with OD.

So, you will be able to gear the axles for good acceleration then use overdrive to keep engine RPM down on the highway. What also matters is the motor is running at / near torque peak for good fuel use with the ability to drop down a gear so RPM rises into better HP numbers for acceleration.

Mercedes seems to run counter to most USA cars by running numerically large trans ratios and small axle ratios.

"""""
Currently I see it like this (if this is even a correct way to look at it...):

300SD (1st gear): 25.3/(3.54*2.88)=2.48
Jeep (1st gear): 32.07/(2.74*3.73)=3.14 """"

The numbers need to be equalized to RPM Vs road speed,

Somewhere there is a conversion formula ( tall tires + high number ratio = short tires + low number ratio )