Underdrive Belt - 20R/22R/RE/RET (Pro 7" Kit with Alternator) 0 Underdrive Belt (Pro 7" Kit) This belt is used on the LC Engineering Pulley Kit for the 7" Water Pump and the 4" Crank Pulley with alternator assembly. Contact our Tech Support Line for... $15.93 Quick view add to cart Add Wish List add to cart