Belgium info

I’m just after a little advice I very rarely venture out of the uk and next week (Friday night) I’ve been asked to run down to bolougne for a trailer swap then across to mouscron for reload.
I’ve done a similar run a few years ago and I believe the route I took was A16, A25, D652, D656, D760 sort of past Roubaix.
I’m wondering if this is the best way in and also I recall some of the tunnels near roubaix being quite narrow and I wasn’t 100% sure I was allowed in them although I never noticed any signs saying I wasn’t?
Any help or advice very much appreciated.

How about 16 / 25 / 19 /N366 to Mouscron
Stop at Steenvoorde for baccy / fuel on way.

You will have to stop at border for the box you will be charged per km it costs about 100 pound but on leaving you can get your money back