shortly after buying an L reg sri 1.4 8v, i had problems selecting 1st and 2nd gear. i replaced the whole gearbox with an F15 out of a low mileage GSI. my standard SRi box, when working, would happily take me to 120mph (although the revs in 5th were high at this sort of speed). now with the GSI box i can take 4th to 110mph but in 5th i will drop to just over 100. Is there any way of gettin my car to do the previous speed with the new box or would it mean replacing the whole thing? Any advice would be appreciated cos its embarrasing gettin overtaken by saxos:(