[Diy_efi] LPG vapor injection with gasoline injectors: calculating fuel requirements

[John Smith1882]

I thought of something that will be a real hangup trying to get my 
MegaSquirt up and running. I need to be able to calculate the required fuel 
for a 400cc single cylinder engine on LPG vapor. I have to be able to 
convert liquid gasoline fuel flow at whatever pressure to gaseous propane 
flow through the same injectors(three 30lb injectors available or four 
26lb). Can anyone help with some formulas or even just links to anywhere 
that show me how to figure out how much injector I'll need?