I am a little gun shy to pull the trigger on a used Grady with F250s since the warranties will be running out in 8 months.  The engines have about 380 hrs on them and they have received their scheduled maintenance.  They are 2005 models.  How many hours should I expect from them?  How many years do we think they are good for?  Is buying used a mistake?
Thanks
	
		
			
		
		
	
				
			Thanks