Trying something new and ned advice

I have a 96 K2500 4x4 that has a blown up 6.5 diesel in it. I have been wanting to put a 427 in a pickup for a long time and never had one until now that I figured was strong enough to handle it. What I need help with is figuring out the ECM that I will need to run this machine. The 427 is coming out of a 94 Chev Kodiak Truck and it ran great until my brother wrecked the truck.
I am wondering if anyone can give me any sources or advice as to who to contact or what I should do for a Brain Box for my Machine. If it was a 4 speed I could probably use the one from the Kodiak but the pickup has an automatic in it . I think the ECM runs some of the functions in the transmission and that is where I need advice. Any help will be great.
Thanks