Read the warranty before you buy. Most crate motors need to be shipped back ON YOUR DIME for repair. If they don't agree to fix it (deny your claim) then you get to pay to get it back. HUGE PITA.
Even if you did your research you can always get a dud motor.
Unless it was an exotic super high HP motor I'd never pay for a crate engine. Cheaper to do it yourself. Plus as many have said you are the ultimate QA inspector. Not some guy on the line at 3:30 on a Friday thinking about getting drunk rather than your motor.
