IMO the only meaningful mod you can do the TBI
itself is bore the whole thing to a bigger size. Unfortunately it's hard to enlarge the top section that holds the injector and that may be the limiting factor there.
Also, where the tbi
fits onto the intake manifold is a circle that is not much bigger than the stock throttle bore so you would need to enlarge that as well.
Honestly, if i was putting together another tbi
setup right now id use a carb intake manifold, remove the piece that goes between the carb and manifold, and make a 2-3" tall spacer/adapter to go from that to a 52mm tb
off a 3.3L, take the top (fuel) section off the tbi
unit, and attach it to the top of the 52mm tb
with alumiweld or jb weld. Bigger plenum volume, better transition in the entry, bigger throttle bore. Ive taken the fuel section off the tbi
and it does seem to sit on the end of a 46-52mm throttle body pretty well.