Agree with priya. have seen many converted vehicles (Couple of CE100/AE100s and FB15s) with no problem. if the Mech. guy is familiar with the thing, then i think it's not a big issue. if you Converting a gearbox to manual one in CR41/42, then you need to buy Clutch pump, manual gearbox with flywheel, Manual instrument cluster(without those P, D, R letters), ECU (if it's a EFI) gear lever and cables etc..I think best way is to get a diesel auto and transfer it to Manual one.