Engine swap in 404

[eurosport]

What is the best choice for an engine swap in a 1961 404? My m180 is seized and I would like to go diesel I’m thinking OM617 but would love to go with OM603. My measurements indicate 603 is too
Wide having intake on left and exhaust on the right

 

[Czechsix]

Diesel or gasser?

 

[Coachgeo]

all 404's were gassers.....

the 0M617a is your best choice 603 is too long if recall right. Newer things are happening though... like stacking two back to back TDI motors has been done now. few other new things as well as the OM617 resources is getting lower.