switching from carb to tbi info please

[1972BackInBlackC10]

so im thinking about switching my 1980 gmc to a tbi setup, i know that the 87 up blazer and burbs had tbi and the trucks in single cab for one yr and crew cab for a few yrs, im just wondering how hard it would be to change out the wiring harness, my main concern is the opening in the firewall for the harness is it the same size as my 1980?

also i know i need an electric fuel pump, however i just put a a new gas tank and sending unit in my truck a couple months ago and i really dont want to remove it again, is there any way i can put an inline fuel pump on my truck and where would be the best spot to mount it?

i already have a tbi intake manifold i still need a trottle body, id have to get the ecm as well can anyone think of anything else id need or im missing to do this swap? any info, tips, links, ideas would be appreciated