4FT light on a 5Ft tank?

[BCOrchidGuy]

If I were to go to a 5 foot long tank and suspend my 4ft fixture over top of it, wouldn't lower light corals etc... be fine on the outside areas of the LR? I have a 4ft fixture with 2 175 MH and 2 NO actinics..... maybe I should upgrade the ballasts and bulbs to 250s?..lol
I may be moving at the end of the summer and I figure it would be easier to move everything into a new tank rather than try to move everything and then move the tank set it up and then get everything back in.