Ah, behold the GM Performance Parts HT 383 in all its glory. It is hard to beat 340 hp and 435 lb-ft of drop-in, ready-to-rumble torque. However, we added to it by using GM Performance Parts cool serpentine-belt accessory system. It comes with all the accessories, such as a power steering pump, an alternator, a water pump and an A/C compressor. The cool thing is that it runs off one belt and all the parts are readily available GM pieces.