Yeah, why not a LT1 (LS1 isnt a good choice for a truck, and they are $$$)? They can be had for pretty cheap and make good TQ. If you really want to set your truck apart from others id say its a good route.
But if you want some carb simplicity, Id go the HT383. Its something like 400TQ and 325HP.
http://www.sallee-chevrolet.com/Chev...8s/HT_383.html
Id say go LT1 though, its very trick. Look around some junkyards in your area, they can be had for a good price.