I appreciate any comments to my project since it helps me with all the issues.
Turbo oiling: to achieve zero backpressure perhap I could run the return into the oil dipstick hole at the bottom of the engine. ( I am assuming that is where it is.)
I believe that the electronic fuel-injection system relies on oxygen sensors in the exhaust to determine if the air-to-fuel ratio is correct. I am assuming that 420's stock fuel injection system will automatically increase the fuel flow if a turbo is added. I have been told that this will work, but am unsure whether the stock fuel pump is adequate.
I am assuming something has to be done to advance/retard the engine's timing to suit the turbo but don't know what and/or how to do it.
I am assuming that the turbo will have capability to monitor its output pressure (atm+ 6 to 8 psi boost) and will activate its internal wastegate to bypass the turbo if boost gets excessive.