We offer several sizes to fit the application. From stock OEM to modified or supercharged engines. 24 lb, 30 lb, 36 lb, 42 lb, 48 lb, 63 lb, and 80 lb are available, contact us for your needs. If you don't see what you're looking for please call or e-mail us. Phone: (480) 753-0208 Fax: (480) 753-0216 Hours: 8am - 5pm M-F Mountain Standard Time