That isn't an easy question to answer. Technically no you wan't get any more power as in noticable power. You will get better drivability, cold weather starting and gas mileage, and the TPI will give you more torque.
Worth really depends on you.
The inital cost of a TPI is going to be more than a carb and a intake if you are staring with nothing. Generally, it will take about $2000 for a conversion, unless you get a running motor with all the wiring etc.
If you don't have anything at all, you are going to need everything from the intake up (85 model is the only one that will bolt on without elongating the holes) intake, plenum, TB, injectors, distributor. You also need a return line and a TPI intank pump or a external pump to feed the system.
Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project