He'd get his @$$ handed to him at the sand drags with an SM465, that thing is too slow to shift, unlike a muncie or something in a street car.
Adam I think an 11" torque converter is a good compromise of driveability and performance in a truck, unless you plan on doing any significant towing, then go with a 12" minimum. Although I do occasional light towing (~3500 lbs) with my 10" converter, it does slip quite a bit, I keep it cool though with my giant cooler. But it is a little looser than I would prefer for a truck, it is a lot of fun on the dunes though!
Edit: After backreading some more I would still recommend a nice 11" lockup converter. And converters are important, don't cheap out on the converter Adam, you'll regret it. I'd call Hughes or another good converter shop, tell them what you want and they'll ship it out within a day or two.