the bigger torque converters are awesome BUT they do not have the adjustability the shock wave has. I'm using the 40 series on my 390 nitrous bike but I had to modify the driver and pulley to do what I need it to do. there are a limited number of performance parts but they fall short of the range you need to race with.i had to rewind the spring on the pulley to hold low gear longer and I had to make custom rollers so the driver would launch at 5500 like I wanted. stock rollers weigh 127.9 grams lightened rollers are 94 the lightest ones are not available so I made a set of aluminum ones that weigh 45 grams with red springs. now it launches at 5500 carries the front wheel for 45 feet on the bars. do some research on the driver parts and see whats available you may have to make what you need,the inch + belt is awesome and will take some ounding, also there is no plate for the 44 it has to have a jackshaft and there are several different length belts that can be used depending on where you mount the jackshaft so center to center measurements have to be right on.