5 speed

Hi all, I’ve just brought a 66 plate 102bhp t6 van. Absolutely love it, apart from a whine that starts once I engage 5th gear? Dip the clutch or change down to 4th and the noise disappears? Anyone else encountered this problem? Not sure if this is a normal noise or gearbox/clutch/bearing fault...

Hi all Looking to buy a T6 but just need clarification on the 5 speed & 6 speed gearboxes. Is 5th gear on the 5 speed box about the same final gear ratio as 6th n the 6 speed. Do not want the van to be over revving during motorway miles. Any advice appreciated.