A quick look at the wheels can help identify what style it is, if it's 8 lugs it's a 3/4ton, if it's 6 lugs it's a 1/2 ton. Most likely if what you say is true, it could have had a different title used to register it.
If you are looking to keep it looking stock, go with the 235, it's a good engine. Several of them are available in the Texas craigslist. Who knows, you might be able to get the engine owner to install it for a price.
