The PS13 had an SR redtop, so the gearbox was exactly the same as all the other blacktop 5-speeds. All the props in these cars are built in 2 parts anyway, so was just a case of splitting the S15 prop and bolting an S14 front half to it.
A lot of people are mislead by information about the conversation as some places state you need certain parts from an S14 as they are different, turns out a lot of the parts were actually the same as on the S15! I might put up a post on the mechanical section stating what parts you exactly need.