I am trying to figure out which orifices I need to buy in order to convert my furnace from NG to LP. The model number is G12RD2E-55-6. Are there some pressure springs I also need?

This is a job not many home owners should do on their own,, sorry but if you don`t know enough about it and need to ask these questions, you should call a hvac tech,, it could be very costly and dangerous if you don`t do it right...

I can definitely appreciate that. I am just looking for the right parts to buy. My brother has some experience with this stuff, but I need to find the right parts.