Ive just put my saphire cosworth away for the winter now and want to sort out some jobs + get more power thro the winter...

One of the main things is the gearbox.. Eversince ive had it it has never wanted to change from 4th or 5th down into 3rd, it goes from 1st n 2nd into 3rd fine,,, wot does this mean?? knackered syncro?? also whos best to get it sorted also thinking about getting it all rebuilt..ifso, who do i spk to or how much is it gona cost roughly...???

Cheers