You should call Inline Tubes (586) 532-1339. Here are the 3/8" fuel supply and 1/4" return lines sets for 81-87 with FI. List for $115 each:
http://www.inlinetube.com/_p/prd14/...87-v8-1-2-ton,-1-4"-f.i.-return-lines-ctf8113
http://www.inlinetube.com/_p/prd14/...87-v8-1-2-ton,-1-4"-f.i.-return-lines-ctf8113
I say
call because - although they do very good work - the product descriptions on their web site are sometimes both vague and confusing. Also it is - by far - the slowest web site I have ever visited in my life. Their sales/tech guys however, are outstanding.
BTW - if you have dual tanks, you will have to rewire your tank switching system to operate the in-tank pumps that are used with the FI version.
You must be registered for see images attach
As used with a TBI equipped vehicle, the tank select system actually has 3 functions instead of just the normal two. In addition to switching tank feed/returns and level indication, the dash switch also energizes/switches the associated in-tank fuel pumps.
Since the power supply to the fuel pump must continue - even after the plumbing and level indication have been changed over - the momentary switch/motorized actuator set up used from 81-86 was not an option (apparently the same wiring harness was to be used in model year 1987).
A solenoid operated actuator operated by a rocker switch (the pre-81 design) was also not a viable option because solenoids only use an O/I type signal - they move in one direction when power is applied and only move back due to spring pressure when power is secured. The fuel pumps each needed their own power supply - that was switched on and stayed on - when it's tank was selected.
So, both pumps needed power even after the tanks were switched over. But a solenoid set-up was only on/off not left/right and a standard motorized actuator would burn up if power was left on for any considerable length of time.
In the end, it appears that Pollak developed an actuator that was specifically for the 1987 model year. It is a motorized actuator with a rocker switch that killed the power only to the motor windings (and continued to supply the pumps) after the valve had shuttled. That allowed GM to use the same wire that moved the valve to supply power to the fuel pumps.
Here read this - it explains it much better than I am:
The information I have is the 87-91 carbureted & TBI trucks used a 4
terminal dual pole dual throw rocker switch (D7089C - #15599081) and a motor
type switch-over valve (not solenoid operated) that included a fuel level sender
switching circuit and switch-over current control (#15548879). This system
was very similar to the previous carbureted trucks with the exceptions of
the rocker switch no longer is a momentary type switch and once the
switch-over valve is in commanded position, the unnecessary current flow is
ended by an switch and diode circuit within the switch-over valve itself.
The left & right fuel level circuit switching is handled internally by the
switch-over valve.