If you want strength before mass then train for strength before mass.

For example doing a 5 x 5 workout cycle for a few months will give you plenty of strength gains with additional mass coming as you get stronger.

So basically, train in the lower rep range for 3 or 4 months and then up the reps to add some mass and give your body a bit of a break. The change will also help your mass building.

The other way is to do a tren cycle, tho still training lower reps. I wouldn't do that until you are confident you can recognise and deal with any sides. In other words make sure you can cope with the test sides first.

Hope this helps. Both suggestions definitely work for me.