hi everyone, i have an oliver 1650 diesel and just had the head done, the injectors rebuilt and the injection pump rebuilt. just eight months after the injectors were rebuilt the tractor started to run rough so i had the injector pump rebuilt. it still ran rough at high idle. went to check for compression and found an injector with like blow back. sent them out again and they said four of the six were way off on psi. new nozzles were then installed and i just got them back. now the question is this wakashau has a copper flared return system which are carefully bent to fit. can i replace it with current tees and plastic tubing? actually the real question is does it run right. don't know, its not together. so what do you think?