MGB front pulley

Dual drive 6061 MGB Alloy front pulley with standard  vee for water pump and alternator plus a 5 rib drive for supercharger hard anodised in black.  125mm for use without decompression plate low boost applications 3-5 psi, 138mm for lower compression use and giving 4-9 psi, 145mm for 7-14 psi   

Boost shown is relative to engine air consuption efficiency , ie standard engine will show higher boost for given pulley ratio than a big bore engine with ported head and high perf.  cam.