1997 silverado actuator

i replaced my front diff. actuator with a used one out of a 91 silverado. i was told that the length of the actuator rods are different. does anyone know if this is true

Let over half of what people tell you go in one ear and out the other.
And check the other half out.

Longer? Not that I know of.
Did you check the auto parts book or salvage yard interchange book?
Was it the upgrader one or the old style 2 wire actuator?
But tell us did it work?

I remember some older ones having a stell plug between the actuator and the fork.

i didnt check the interchange manual, the hollander that i have does not have the actuators in it. but the plug was still a two wire but the plug style was a little different. my 4 wheel is still not working. when i put it in 4lo it sounds like it locks in and drives like it is locked in but the tires do not spin. also 4hi doesnt do anything. and other suggestions would be greatly appreciated. from what ive been reading all the same symptoms lead to the actuator.

How are you checking for front axel lockin?
Does the actuator get power and ground?
They work like window motor with reverse power on ground and hot.
Jack up right front wheel in 4W wheel key on/
Can you spin right front wheel or is it locked in?