[Yukon Jack]

What year vehicle are you asking about. You will find there are no definites.

With a 4 inch lift your driveshafts should be fine, but occasionally there is an issue.

I did have an issue with the initial 4" lift I did on my 69 K20 - the front driveshaft was too short and I ended up having to add a Double Cardon Joint also.

Depending on the year of vehicle usually a raised steering arm is recommended to get your steering back to near stock. If you dealing with a 69 or older, you will need an adjustable drop drag link as a raised steering arm isn't available for the axle used in a 69 or older truck.