Is it safe :0

Is it safe to turn the engine on after installing the upgraded injectors and what precautions should be

Taken into account before and after installation (mostly ecu/computer tuning wise)

What sort of percentage increase in injector flow rate have you upgraded too?

Hi Green

going from stock 26lb to 69lb at 43.5psi

If you are using a VE based ECU, just change the injector flow table.

If it is injector pulse width based, you are going to need to take some pulse width out. I'd start with removing about 25% and then see if it starts/runs. Some ECU's software have a function to do this.