Most suspension kits that use Corvette stuff switch the front to coilovers. If yours is still the monoleaf the standard way to raise and lower the front of a Corvette is to change the links between the monoleaf and the arms. A lowering kit for the front of a C4 Corvette costs like $20 new.
I'm not sure the way you describe will raise the truck, but if you study that suspension changing those links is the way to make small changes in height.
Last edited by OldSub; 01/15/2010 4:21 PM. Reason: More thoughts