There are many builders who do the big reed conversion so i wouldnt suspect just one person did them.Yes they do seem to run better with bigger carbs.And the spacer is on there more then likely to keep your carbs off your clutch actuator so i wouldnt toss them out tell you have them on your bike and make sure your bowls are going to clear it.Plus sum builders prefer the spacer anyways.
they usually do yz reeds when they do the conversion to big reeds.Tlke to jeff at F.A.S.T on here he has done big reed conversions.try looking up yz250 or 125 reed cages see if they bolt up..I have never heard of doing blasters.Only using blaster size pistons.looks like this to me http://cgi.ebay.com/ebaymotors/YZ250-YAMAHA-1990-YZ-250-90-REED-VALVE_W0QQcmdZViewItemQQhashZitem562cf04ea5QQitemZ370121133733QQptZMotorcyclesQ5fPartsQ5fAccessories
regardless of color he is a socialist which is BAD NEWS...He is for strong government,taking guns away,and owning banks,,3 strikes your out right there if you ask me...
its whatever you get comfortable with...if your comfortable on your bike and know where,when,and how it will come on you have an advantage of someone that just has a bike thats built better.
dont worry about the duechbag comment from that guy...whatever you have for sale post it...it would help you not recieve LOW ball offers if you gave some sort of starting price.