The Dime owns the record book on it's factory suspension. Stop reading things on the internet.And again,the factory stuff is superior to any Shitstang II stuff.
If you do the swap,top end will improve,low end will vanish,the truck will be a dog at anything other than freeway speeds and it's ability to carry weight will be gone.ANd if the gear swap is low enough,the resulting cruising rpm could actually make fuel consumption worse.
Just tossing another set of gears in there is really not a good idea.THe gears & box came from the factory like that for a reason.Rule of thumb is for every 10% increase in power,you can decrease the gear ratio the same % with no adverse effects.If you just drop the gear ratio something,somewhere will change for the worse.