Guys have been plowing with one wheel peel rear end trucks for years. Some guys actually prefer an open rear diff. over a LSD/locker because the wheel that doesn't spin, helps a little to keep the rear of the truck from wanting to kick out in one direction or another.
Me, if I buy a truck, SUV or rear wheel drive car that doesn't have a LSD/Locker, I have one put in. Just my preference.
Not sure what's available from either the OEM or aftermarket diff's. for Toyota's.
NYH1.