Help 1969 chevy c10 SSB and installing a 2019 6.2 GM

I am doing a complete frame off on a 1969 chevy c10 SSB and installing a 2019 6.2 GM motor with an eight speed transmission. with a "Drive by wire" pedal. I do have the complete wiring harness that came with the motor and tranny.
Question - Will I need a new wiring harness for the motor? Will I need the the computer reworked - I am keeping the motor complete stock (daily Driver).
Would you help guide me in the right direction?
I was told I need to change the flat floor pan to a hump floor pan to accommodate the 8 speed tranny. ???
Any and all help would be appreciated. Thanks in advance!