Hiasley, Schied, Enterprise, Powerparts Eng, Extreme diesel. The hardest part is pulling the cam to swap out the front timing cover. It all depends on what you are looking for. Dependable pump with unsurpassed fuel capabilities and horsepower but unadjustable power, then it is hands down the better choice. If you want the snappiness and adjustability of electronic boxes and better street manners, the stay with a hotrod vp. Tim