its questionable with the 8546 billit,,,,im running the 8387 billit vac adv model and theres plenty of room..
id run the 8387,,,u get ALL the advantages of the billit plus the advantage of vacuum if u want it...
as far as adjustablility goes,,u cant beat msd,,if u ever have tried setting up the other brands,,i have,,there not fun,and dont set right,and stay set,,i hate msd's marketing..but they have there s%^t together,,,run it with or without there on board electronics,,,,if using after market heads some clearancing will be involved,440,but it will clear the shaker..