Putting TBI into an 86 K30

[KenMasters]

Ok, I bought an 86 K30 truck with an already installed chevy 350 tbi engine in it. Recently my computer died. My question is, which PROM codebase should I be using for this application, for the one in it now runs like hell. It came out of a 91 Blazer. The guy I bought it from didn't install a VSS, so I'm sure that contributed to the problem. I ordered one from stealth conversions - so now I just need to replace the ecm. Current codebase is ARJT (obscure one I believe). Any ideas?

 

86 Chevrolet K30

TH400 tranny

Dana 60 rear end with Detroit locker and 456 gears front and back

 

Thanks in advance,

Ken