Ebay has Dale NH250 aluminum resistors 6.8 ohm 250 watt for 9.99 apiece. The guy has 11 of them at this price apiece. These will probably work although they are one ohm off. The auction number is 1730182463 and it ends in 19 hrs. It is now 8:12 pm EST on Sat.. Hurry if you want them😉