i have a 99 jaguar xjr and i need the stock crank and blower pulley specs. id alos like to know the aftermarket specs too. im machiining my own pullies to get the psi that i want . if they workout right then i willbe making aand selling them for a lot less then eurotoys or ebay. theyr being made of billit alluminum have decided which billit to do and they will be much easier to install and not have 6 week wait like eveyone else they will bolt over your exsisting crank pulley the sc pulley will still have to b changed. im gonna start with an additional 6 psi and then 8 and then 10 to c how it holds up thanks for any help. and does anyone know a good site to do size caculations