So i bought a polsihed set of underdrive pulleys and finally got around to putting them on. They were made to fit a 90-99 SBC vortec 350/305 but i asked the owner if it would fit my motor and he said yes. Well i put my new belt on and relized while the engine is running that the crank sits farther back then the waterpump does so only 4 out of the 6 ribs on the belt is on the crank pulley. Im guess its because I have a long waterpump and not a short? Is there anyway to space the pulley out farther from the crank so it will line up with the waterpump or do I need to just buy a whole new pulley???

Id had an idea to go to a 4 ribbed belt instead of a 6 but im not sure if it would move back and forth on the other pulleys at high rpm. Any suggestions??