1.8 gearbox on a 1.6?

Hey guys, I am still kinda new to the forum. I have searched for this topic but could not find anything so have decided to start a new one, sorry if it is already out there. What I am looking to do is fit a new gearbox to my car, as I suspect the sycro between 1st and 2nd is going. It has become difficult to change into 1st going down from 2nd and from netural, changing up to 2nd has a bit of a clunk/clash almost like a grind when the gears go together. I have found a 1.8 gearbox for a good price, thing is I have a 1.6. So main question is will the 1.8 gearbox fit and how easy is it to carry out? I have heard of this being done before just wondered if the gearbox is the right route to go down and if there is anything else I will need to change.Thanks for all the help and advice.

Early gearboxes were always a bit stiff, especially cold, changing 1st to 2nd; there is a huge difference in quality between my 100k 93 1.6 and 160k 96 1.8; the 1.8 has a much nicer change. Any Mk1/Mk2 gearbox will fit. I assume you have already ruled out problems in the clutch hydraulics (failing slave cylinder, failing master cylinder) and that the shifter bushes aren’t damaged; the £3 snap on nylon bush at the end of the gear leaver can split, and can make 2nd-3rd changes a bit hit and miss. The gearboxes themselves rarely go wrong.

In fact I haven’t checked the hydraulics or the bushes so I will give them a check before making my mind up to switch. I have changed the gearstick gaters and nylon bush as I thought this might help but hasn’t changed much.