carb to FI

[hobsiscool]

Ok i know i have asked this before, but...

I have an inline 6 in my 81 truck w/ a carb.
I have a 350 V8 in my 89 truck that's FI

what is all involved in swapping the FI engine to the carb truck?
-Is this a very expensive thing to do if I were to pay a mechanic?
-can you go from FI to carb? what would be involved in this?

I have the computer and engine in the FI truck obviously and it has the t350 transmission.

any help is much appreciated!