F10 motor quiry


Hi fellow daihatsu owners. I have recently bought meself a F10 Daihatsu 4x4 (1977) its motor will need replacing soon. No-one in my country Australia has a motor for me hence my quiry: does anyone know what other motors would be compatible for my car or has anyone converted an F10. Was also wondering if anyone knows where i can get a workshop/service manual for my car. I am a complete beginner at this and hoping someone can help. Thanx