Hitachi EX300-3 and EX310H-3C excavators:
Operating weight: 30,700 kg (67,700 lbs) for the EX300-3 and 33,900 kg (74,800 lbs) for the EX310H-3C
Engine: Isuzu AA-6SD1TQA diesel engine with a net power of 184 kW (246 hp) at 1900 RPM for the EX300-3 and 200 kW (268 hp) at 1900 RPM for the EX310H-3C
Maximum digging depth: 7.68 meters (25 feet 2 inches) for the EX300-3 and 7.95 meters (26 feet 1 inch) for the EX310H-3C
Maximum reach: 11.78 meters (38 feet 8 inches) for the EX300-3 and 12.29 meters (40 feet 4 inches) for the EX310H-3C
Bucket capacity: 1.8-2.2 cubic meters (2.4-2.9 cubic yards) for the EX300-3 and 1.8-2.5 cubic meters (2.4-3.3 cubic yards) for the EX310H-3C
Some of the part numbers you mentioned:
9135325 and 9135612 are part numbers for swing motors used in the EX300-3 and EX310H-3C excavators.