Hello, just looking for an opinion here. My 1991 Alltrac manual van with 220k has a cracked head. This was determined by two different mechanics, one who works exclusively on Previa's in the Seattle area. He will repair it for $1600 which is much less than other quotes. My question is this: the van shows no signs of running badly, losing oil, losing coolant or any symptoms associated with a cracked head. In fact, it is quite likely that I have been driving it like this for the last two years-and on many long trips I should add. Should I just keep driving this van keeping an eye on colony and oil levels or buckle down and do the repair? Thanks.