okay i know this swap has been done so imma start to do mine. i already have a b20 motor in my civic now i want to go vtec mode haha. what are some problems that im going to encounter knowing that the pistons on the b20 is a little larger than the smaller brother the b18 so will the valves and the piston hit if adjusted too much on either intake or exhaust side. what is the best way to approach this thanks.