ecm question?

I have a question on ecm's my truck is a 1999 classic it has the 350 vortec I know its not an ls but I replaced the motor in it and it came with a cam so I been running the cam and the ecm is tuned by nelson and im wanting to go back stock. stock cam and ecm. my question is can u use any vortec 350 ecm's. I found a 98 ecm and was wondering if it would work with out any tuning done to the ecm? im not sure on this and need some help?

Im pretty sure the ECU would need to have vats deleted or set to what is currently on the one your using. I could be wrong though