Any engine we sell 3 or more times a year we try to keep in stock ready to go. For most other applications we have core engine inventory available to build. The average lead time for an engine to replace a stock application is between 2-3 weeks. An engine with special modifications (A large percentage of what we build) will take longer. Hi Performance, Restoration, Industrial, Antique Auto & Antique Marine will be quoted after evaluation and consultation with the customer.