looking for help with engine timing

im working on a 73 240z, with a 79-80 280z engine....code l28e(that is the code on the cpu and block), it is also turbocharged....

the engine was just rebuilt and the car fully restored...im in the final process of completion, but cant get the engine to run.....has fuel and spark to the cylinders, but wont run.....has to be a timing issue.......an help would be greatly appreciated....thanks James