I'm with Rex on this one, nothing wrong with a couple of hours practice in a 737 just to remember what trimming is like (after flying Airbus for years).
Whoever's assessing your sim will be experienced at the game and will know straight away if you've spent several hours having a go at it
They'll also want to know you've put the work in, nothing wrong with being keen. Not doing some practice may be seen as being lazy.