Rothsport offers billet aluminum crankshaft pulleys for Air-Cooled cases utilizing the GT3 crankshaft.
The 125mm racing pulley is for high RPM 3.6, 3.8, 3.9 engines and requires a 740mm belt.
The stock diameter 145mm pulley uses a 776mm belt.
A/C Pulley for Air-Cooled 3.6 - 3.9L
Case w/ GT3 Crankshaft