I recently purchased a 2009 Silverado 2500 HD with a 6.0 l. The truck is from back east and was never equipped with a block heater. Here in Alberta it can hit -35 C. at night and even colder with the wind so a block heater is defininately a requirement .Not impressed with the reports I'm hearing about the factory block heater and was wondering if anyone has a recommendation for an after market unit? Thanks in advance.