dedicated lines, equal length?

I just moved and need to run dedicated lines for my system. I'm using monoblocks and have the speakers along the long wall so there is a signifcant diffference in the length of lines required to run the front end and one amp and that required to run the other amp I estimate about 20 ft differce with about 75 ft required to run the longest line. Will this make much of a difference or should i run equal lengths and just loose the excess for the one side around in between the joists? thanks