Occasionally we get back alternators from customers on stock adjustments or warranty repairs, where the customer chooses to upgrade to a higher amperage unit. These alternators are used, but refurbished to like new condition and performance. They appear brand new, and have new rectifiers, regulators, bearings, and and rotors. Refurbished units come with a 90 day warranty, and can still be repaired inexpensively if the customer has a problem outside of the warranty period. This unit features a large case hairpin construction with huge press fit diodes, a heavy duty 4 pin standard GM voltage regulator, and a billet pulley. These units make a minimum of 200 amps at idle with 320+ amps at cruising speed. (typically they make closer to 350 amps peak) These units are a great way to get big power on a budget. NOTE - Like most high output alternators these units come with a smaller pulley, and will require a slightly shorter than stock length belt, which can easily be purchased from your local autoparts store. ALSO: YES! THIS WILL FIT YOUR 4.3L BLAZER ALSO. IT WILL NOT FIT A 2005 AND NEWER GM TRUCK, THAT IS A DIFFERENT PART WITH A DIFFERENT REGULATOR. IT WILL NOT FIT YOUR PUEGOT, VW, HONDA, LAWN MOWER, OR NISSAN PATHFINDER, SO PLEASE DON'T ASK! LOL.