I'm carbed, but if I had a factory TBI and was considering upgrading the engine underneath it, I'd give these guys a ring:
www.pcmforless.com
(the following is quoted from their FAQ)
For your GM vehicle we can:
· Change the fan turn on temperatures for a 160° thermostat.
· Program the transmission to perform similar to a shift kit (1994 and newer). and delete the dreaded Torque Management
· Power program the car for use with premium octane gasoline.
· Remove the top speed limiter.
· Correct the speedometer and transmission for gear and tire changes.
· Correct for the use of a larger throttle body.
·
Change idle settings and restore drivability with cam installs.
·
Correct for larger injectors.
·
Correct for larger displacement (383, 396, etc....).
. Improve mileage especially on the 99 and newer trucks.
· And more! Just ask if you want something done that isn't listed.
The bold stuff would connect closely to making significantly more than the stock 210HP of the '89 motor.