Do not create then drop a clustered index. If you want a heap, live with the extent fragmentation. It's far less damaging than logical fragmentation. If you want to put a clustered index on, then put one on and leave it there.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability