People make great ballast! Or u can always get leadheadz, or ballast bags tend to be kinda pricy but they are very easy to move arround, just throw it where u want it then throw the pump over the side an in like 5-10min u'r good to go! Tbird is right tho... an 85hp might not handle a lot of ballast very well... but ya never know till ya try!
Good luck and have fun!