Not a Golf engine...

Hi guys. It's been over three years since I've been on the forums having traded my Mk1 cabriolet for a T25 camper. I still have the latter but my plans for a full restoration never came to fruition. Anyway, that's not why I'm back. I have a question that I think the members here might be able to help with. I'm off to see a 1983 B2 Passat later. It's got the 1.9 L I5 (straight five) engine and covered over 170,000 miles. The Golf never had the same engine but I wonder if anyone knows any 'compatible' engines that might be considered a replacement, i.e. that'll fit on the same mounts (minimal effort)?

Actually, don't worry now, it was a shit-box. Water in the oil, auto-choke shot (started revving at 2.5k and slowly increased), various electrics not working. Can't believe the guy had it up for nearly a grand!