This flywheel is used in the Camaro and Firebird. It has been re-machined to fit the 3800 Fiero conversions. This flywheel weighs 22 pounds prior to machining. We remove 6 pounds of material from the facing to enable the clutch to fit properly into the Fiero transmission. The bolt pattern fits the stock Fiero bolt pattern and the crankshaft bolt pattern is for the Series II Supercharged and normally aspirated engines.