This guy did a TBI set up for $325 after selling a few parts.
http://users.sfo.com/~eagle/howell.html
Aftermarket TBI kits are plentiful and under $1K. Look at TBI systems from
www.jegs.com and
www.summitracing.com.
Find a 96 and later 350, add TBI and you've got a great truck with FI, milage and power.