Getting ready to swap an LS1 into my 87 Pickup, need some help

[UATahoe]

I will be swapping in an LS1 out of an 01 SS Camaro and I have the harness and computer. My truck currently has dual tanks and I want to keep them. The in tank fuel pumps have already been upgraded to the ep381 pumps on both sides because a swapped in a 383 about 2 years ago I guess. I kept it as a fully functioning TBI system. So moving forward, am I going to be able to ditch the entire tbi harness and computer when I swap in the LS? Or is the factory ecu still needed? I was hopping to rip it out and ditch it all together.

[Matt Cramer]

You would be using the LS1 computer and not the TBI computer. (Unless, of course, you go with an aftermarket standalone and don't use either one!)

[UATahoe]

Yep, I am going with the ls1 computer. About to send it out to have it modified. I have been looking at diagrams of the 87 fuel system. It looks like the fuel tank selector switch in the cab is indeed run through the factory tbi computer. It should be an easy fix though to bypass that part and remove the tbi computer.

[BR3W CITY]

You'll have to make sure that all the lines are EFI compatible as well. I'd think it would have been changed since you switched to high pressure pumps, but if you haven't you'll need to.

[UATahoe]

meaning the lines running from the fuel sending unit and pump assembly back to the selector valve? The 87 had the factory fuel injection installed but that hose isn't adequate?

[BR3W CITY]

Every line that isn't a hard line. The 87 "fuel injection" is sort of a loose use of the phrase. Those are low pressure systems which generally operate on standard fuel line (which is NOT modern efi safe). The LS systems operate 55-62psi at rail pressure, with pre-regulator line pressures able to go much higher. Standard fuel hosing is not reinforced and will hemorrhage and lose fuel, which will either result in a leak/loss of fuel pressure/fire/explosion/people crying...or just a minor leak and a generally unsafe condition.

[UATahoe]

Br3w, really appreciate the information! I will be sure to change out all of the lines. Should I do all lines or just worry about the feed lines? Return lines and vent lines should be fine as is?

One other question. I have dual tanks. Any suggestions on a fuel selector valve? I bought a new one but it says it's only rated to 65psi I believe? I tried finding the pollak valve but it seems to spec out the same 65 psi rating.

Thanks again for all of the help!

[UATahoe]

Anybody have anything to offer on a reliable tank selector valve?

[BR3W CITY]

Considering that the ideal way would involve running two entire pump/sender assemblies, I'd be looking to avoid that setup. If I had to have the extra capacity for some reason, then I'd run one tank off a level sensor and use a transfer pump to keep your main tank filled at all times. Thats the way I'm used to from RV's ,boats, and airplanes.

...but my spine wears out after a few hours anyway, so I'm not the "6 hours straight" kinda driver.

Found the oldschool thing I've seen setup before for multi-fuel.

[UATahoe]

Truck currently already has the delco ep381 pumps in both tanks and new sending units. Kind of pot committed at this point. Lol

[solidaxel]

A thought for dual tanks, instead of a transfer pump, could you switch the return line with a valve and a "T" fitting?
It would take some close monitoring!

[foamypirate]

A new replacement switching valve for an 87' will work fine. I know a couple of folks running them with no problems. ACDelco sells one, exactly the same as the Pollak valve (in fact, it's the Pollak valve in an ACDelco box). Pollak has confirmed the 3 port version is identical to the 6-port, just with glued caps over the unused ports. You can remove them and run it as a 6-port. The 3-port valve part number is much cheaper than the 6-port part number, even though they are the same exact valve.

[UATahoe]

Thanks for the info! I will give it a shot and see how it goes.