If keeping the driveline stock, there shouldn't be any major costs. Fabrication is another story though. The Achilles heal of the whole project is the oil pan. I have a 54 truck. The engine could be mounted higher in the engine bay to compensate for the oil pan clearance issues, but then there is the issue of trimming the fire wall and building a partial tunnel. If I had a MII suspension it might not be such a big issue.