I had a Ford van with a 300 6 cylinder with a bad freeze plug behind the motor mount. I was able to get the freeze plug out without too much difficulty and used an expandable soft plug. It was not difficult and worked great.
Just to help with you decision... I see nothing wrong with using the expandable plug like these guys suggested.
Not good for show judging and points but for some reason I think you'll be fine for awhile. More time for beer though.
Just measure the diameter of the hole before going to the parts house. They are going to ask and there is no year and model for this part - generic.
This is what you'll be getting if you go this way. Has a rubber puck that goes in the hole. Picture credit to Bolter 'Daniel-Rose'.
http://s995.beta.photobucket.com/user/hootschc/media/20thfeb2013truck001_zpsd3873d84.jpg.html
