The early HD trucks were just 5.4's. In 02' (Icould be wrong) they were S/C. Exactly the same as the Lightnings with the exception of the upper pulley.(it was bigger) On to the new style... There is a ton of variations to the HD. Some can be had with the S/C. Not to mention the bigger Super Duty HD's with or w/o the Powerstroke.

So which were you referring to? lol