engine swapped now wont start???

[Godspeed]

first off im a noobie to the diesel and power stroke world so please try to bear with me... ok heres the deal im working for a friend and he has an 01 350 dually 2wd he swapped the engine from 99 350 into it it was a running and driving engine before now that its in the 01 it does nothing. he thinks if i switch the dash harness then maybe it will work and maybe also the fuswe box???? oh and the gas pedel because of the wiring to it??/ my ? is. do i really need to ge through all of this or is there another way to configure this swap? as far as i know he says the obd2 port has no signal????. the deal with the truck is he says if i fix it i can have it!!!! so im gonna give it hell i will be going to work on it today also i will get exact yr date and all other info.. i have searched on here and found that there is a difference between 99 and 99.5 and00-01 but is there a big difference in the computers and fuse boxes? like i said im new to the power stroke turbo diesel i have been building mostly the toyota supra turbos for the past 10 yrs but im eager to learn and for basically my labor i can get the truck im stoked.

[Godspeed]

ok so after changing the harness for the dash out all the electronics went crazy and the interior lights would flash like emergency flashers lol. i convinced the boss to let me put back the original harness. so now all the interior stuff works again. but the engine will turn over but not start..... it turns kinda slower than i think it should even with good batteries????? the boss also keeps trying to spray ether into it to make it run!!!! as far as i know your not supposed to do this right? he said the engine ran perfect in the other truck right before they pulled it out. the engine is a 4/99 7.3psd and the other truck that it went into is a 1/01 that had a 7.3psd both manuals???

[00forddiesel]

I would definately stop spraying ether. If It ran before it will again without it. Hopefully someone else can chime in but im thinking you need to get an ECM and IDM from a 1999 Manual. I'm not sure if thats an early 99 or not though.

[Godspeed]

they did take the ecm and idm from the 99 truck i wanted to check all the little stuff first then get into major things later... i noticed when he sprayed the ether into it it would almost slow the engine down when it tried to start. idk but im gonna figure it out some how.. thanks