Just a heads up on this. The early Walbro 340 pumps were narrowerer and used a different sock that the newly designed ones.
A number located on the pump housing will idnetify which 340 you have. One posibility is "GSS340" cant remeber what the other one is, but you will have to determine which one you have first in order to get the right sock. Then call Precision Turbo and talk to Patrick (phone # 219 996 7834), he will get you the right one.