Depending on your engine options, configuration, etc. there is no one size belt used on the 4bt. But there is a pretty narrow selection and a 8 rib, 53" belt is in the ballpark. The number you listed is 8 rib and 53.7" long, well within the ballpark. Take it home and see if it fits. Due to limited throw of the tensioner on my engine I need to slip the belt onto a smooth pulley last. If I try to install it on a ribbed pulley last it is too short and the next size larger belt is too big.