1st try
level - 7
lines - 70
score - 13920
it starts to get too fast at that point for me to reorient everything in my mind when rotating. I could probably get to level 8 if I practiced and if I hadn't made a few mistakes earlier forcing me to have a shorter playing field.
edit: i destroyed my score on the second playthrough with a whole ton of tetrises, but only got to level 6. I'll have to try again later
new high score - 18600