What do you do with the hose to the crankcase if you use the block-off plate's?
the hose connect to the air box, so nothing is required to be done. you do however have to block the hole in the air box that the hose on the kleen air pump was connected to.
if someone had done the "crank case vent mod" the hose from the crank case would have been routed to the valve cover. in this case run it back to its original location on the back of the air box, or to a "puke tank" or put a breather/filter on it. DO NOT restrict(or worse block) this hose or you will blow seals at high rpm(i had a very restrictive filter on at one time, so i know..)
as far as cheap block off plates, its very easy to make your current plates into block offs. take them off, remove the hoses and fill the hole(in the plate) with JB weld or have them welded shut, or tap and screw in a NPT plug. personally i have Muzzy block offs cause i found a set second hand and they are pretty:thumbup: