Yep, it will overdrive your 54w lamps to 85w a piece. You will need a fan to blow end to end. The bulb's won't last as long when you overdrive but the added brightness and par is worth it imo.
I'll know for sure soon cause I had brand new bulbs started burning on march 20th, And burn for about 3 hours in the morning and 3 hours at night, two individual reflectors on top of the tank at a 45 degree angel..
two fans in the hood at one end blowing to the other.
So the test is on.. LOL
I had three 250's over my tank before the t5's and the mh's didn't come close to the amt of light the t5's put off. I love them. Jnarrow has ALOT of light or did (over 4k watts)....we aren't even at 1k watts yet! lol