Old Burb

I have a 1989 Chevy Suburban with the TBI on it its a 3/4 350 with TH400 . I built a new engine for it a few years back Put a comp cam roller cam and rockers flat top pistons and some RHS after market Vortex heads and the new intake to go with it up graded to the 454 base and the good 5.7 injectors and put in the new fuel pump in the tank for more pressure and had a new chip burned for it . The problem is I know its now running as good as it should be didn't make much more power then the old engine and the gas mileage is so bad . So I was thinking about up grading from the old slow TBI stuff and going to the newer vortex computer and injection and then I could up grade to a 4l80e . But I have not found a lot of info on this swap . So as I was looking I found a guy putting in a 0411 computer swap in his suburban with the 454 . I know there are a lot of after market set ups out there but I don't want to have to reinvent the wheel . I know its going to take some work to do it . Do you think that if I got the wiring harness off a 99 Chev truck and the injection system that . That you could get the pin changes to make the new stuff work or is it more work then its worth