I beleive the XL is a V6 where as the XLT is a V8 and the Sport is a V6. So as far as I know the XLT is the only one with the V8 (except the Lariet, HD, Lightning etc.) The sport comes in regular cab and extended cab, the XL I don't know, and the XLT comes in regular cab, extended cab, and four door. (I am talking about the older models though not the new ones cause I own a 98 and I am not to familiar about the new ones)