Tractor Repair: engines, david brown 990, rare tractor

Question
Will the David Brown 990 or 850 engine fit into the Oliver 600

Answer
not 100% sure but the 850 engine should definitely fit. some of the later Oliver 600 tractors were actually 990's but most were David brown 950s i suspect the engines are the same fitting but the 850 0r 880 would have less power than a 990 or 950. the 850 David brown was known as an olive 500 the 950 was a Oliver 600. you are the owner of a very rare tractor not many left in this guise only just over 2000 sold by oliver the engine David brown used for these is one of the most economical engines ever made they would run on a smell of diesel