It all depends on how you plan on driving the truck and any changes you have
planned. If you are never going to put a sticky tires in the rear, no suspension
mods and 95% of all your driving is cruising, then I think you might be OK. You
will never be able to load the trans enough hurt it.
But then again if it's a used trans and you have never been thru it, you don't
have any idea what it's going to run like.
Assuming it a used trans, I would go thru the trans and replace seals and friction
disks as a minimum. Then depending on how you plan to use it, make any needed
modifications that Strictly Attitude is suggesting. Sounds like he knows the weak
spots in the 700-R4.