Gutted !

i have done all the measurements and checks and i just cant get my cummins into the mog without cutting the chassis . its too tidy to chop it about so i fear i am resigned to finding another perkins 4 cylinder . i just cant find one inside my budget . if anyone here knows of one i would really appreciate it . on the other hand i was wondering what other diesels may fit and if anyone has one to sell please . Any help would be really welcome .
All the best Kev