87 fuel system in a 86

[BamaDave]

what will I need to do. I know tanks are a direct fit. Will 87 sending units hook up to all the 86 stuff? (wiring, hoses)

I am thinking on trying the new Holley Terminator.

[rfmaster]

87 Fuel system includes in tank fuel pumps and was designed for TBI motors. 87 fuel units are different. 86 fuel system was designed for carb application - no in tank fuel pumps. TBI systems uses 3 lines - fuel supply, fuel return and vapor purge. In tank fuel pumps require switched power source - controlled by ECM.

What are you trying to accomplish with 86 to 87 swap??

//RF

[BamaDave]

I want to use the new Holley Terminator EFI

[BamaDave]

I'm going to bring this back up. I have changed to a LS swap from the Holley EFI. What do I need to add/change to make the 1987 tanks and pumps work? I have the 1987 cab fuel valve switch. Do I just need to rewire from the switch to the valve connector, or will I have to add wire from the connector to the pumps?

[Tilt]

If you are staying with dual tanks, you will need the 87 and up tank switching valve along with the in cab dual tank switch. You will also need new fuel pumps for the 87 sending units. If I remember correctly, the 87 pumps were low pressure pumps and the LS needs roughly 58psi.

[kalbert]

I think you'll be time and money ahead to just do a single inline pump vs trying to get in tank pumps to work.

[MalibuSSwagon]

Well, if you already have everything working (dual tanks, switching valve, etc) then just run relay turn on wire to correct pin on your ECM, swap out fuel pumps for AC Delco EP381s, and plumb the 3/8 feed and 5/16 return to the fuel rail, or to a Corvette regulator filter if using a returnless rail. Should be fairly straightforward, especially since you already have EFI on the truck.