This precision made BHJ harmonic balancer is already zero balanced and fits into the 1989-1993 Ford Thunderbird. If you have any doubt, err to the side of caution and go to a machine shop to find out. Think twice before you replace your stock balancer with one from a large automotive outlet. They are NOT even close to the same quality and performance. You will find yourself replacing that less expensive model...so do it right the first time with BHJ. We are proud to announce that we now carry the BHJ SFI aproved all steel balancer rated at 6500 RPM and above for the 1989 to 1993 and also the 1994 to 1995 for the 4.2L or 4.3L engine or for the 3.8L for the Thunderbird SC Hot Rods Mustang Transplant or Super Coupe!!! Please ask for our Specical pricing AND free bolt and washer! special of the month. Save $18.00 or more!!!