Hi, I just bought a 1980 320i with a blown engine. I think it is an iS because it has recaros, 13" bbs, and the three spoke steering wheel. Any other mechanical differences between i and iS? I am new to bmw sso any info will be greatly appreciated. I don't think I want to repair my engine as Im thinking of installing an e30 2.5. Any one know where I can find out info for the the swap? Thanks guys! Mike