None comes up on ebay or craigslist so if you can not find a "F2TF-JA" or F2TF 12A650-JA at your local salvage yards you may have to go with a remanufactured unit.

 

I am working on a 1990 F-150 with a 5.8 Automatic 4x4 California emissions. The truck is broke down 1hr away from me alls I can get from my uncle is the calibration code he cant pull the ecm. : 0-64R-R12 : can anyone give me the engineering/part number and interchange for ECM?

 

For the calibration code of 0-64R-R12 with a 5.8L EFI.
PROCESSOR AND CALIBRATOR ASSY (ECM/PCM), (EEC-IV) the engineering number is F0TF 12A650-PD and the Ford part/service number is F0TZ 12A650-PD.

Note most salvage yards and auto part stores go by the engineering number and the Ford dealers go by the Ford part/service number.
Some online stores will drop the 12A650 as all PROCESSOR AND CALIBRATOR ASSY (ECM/PCM) have that for their base number.
So online you might look for F0TF-PD or F0TZ-PD.

 

No it does not matter if it is from 2wd or 4wd when it comes to the ECU.

You did not state the year of the 302 engine or what wiring harness you used so I can not answer the other questions.