4.3 TBI to 5.0 TBI swap

[kevinr1970]

I think I have everything in order to make the swap but have some electrical questions.

I was told that the harnesses are the same but will need to swap the chip (or controler?). Can I just swap the whole box the harness plugs into?

For the engine (5.0) from the donor I just took the whole harness. This includes the external part of the fuse block on the firewall, the computer(?) mounted under the dash behind glove box and everything attached to the engine/alternator/starter.
Can I just plug this into the fuse block on the recipient truck?
If not, the recipient truck was two headlight and I am putting in a four headlight core. Will that portion of the harness/fuse block just plug in?

They are both '87 2wd trucks. The donor was a Silverado with all options and AC. The recipient is a Custom Deluxe with no options - no gauges (lights in the dash), no dome light, manual everything including tranny, etc.

Any help is appreciated. Thanks.