Hi, I,m from the basque country(north of spain) and I'm the owner of a volvo 340. I started a f7p conversion and I would like to know if I have to remove the brake booster from the original place (I have it on the right side of the engine). thanks for listening and sorry for my english.

Don't worry about your English, you can be understood well.

I can't think of any left hand drive F7P's that exist to help you, most of us who have the conversion are in the UK so drive on the right and it's fine. The closest I can suggest is look at the project thread by user "340cbr", he put a B18FT into a left drive 300 in Portugal. The B18FT is a non crossflow head (both manifolds on the "exhaust side", your passenger side) but you'll get some idea maybe?