Author Topic: 1985 to 1987 Fuel tank & pump LS swap ... do myself or buy kit  (Read 152 times)

Offline dogfacedsoldier

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1985 to 1987 Fuel tank & pump LS swap ... do myself or buy kit
« on: September 14, 2018, 09:13:53 AM »
I have completed an LQ4 swap into my 85 C10.

I'm currently running an external pump to the left tank (stock fuel lines run from engine to left tank & relay, to right tank).  I originally wanted to find a way to run both of my tanks with in tank pumps, but as I dig dealer into the mods, the novelty vs. work/$$$ ratio doesn't make much sense (could put that time and $$$ elsewhere).

So I am going to run fresh lines to the right side, as this is more of a clean slate than running to the other side.  I will plug the stock lines to/from the left side, in case I change my mind about tackling dual tanks.   

I have checked out the conversion posts, installing a stock 1987 baffled tank, modified stock 87 sending unit, and upgraded pump. 

There are also a couple ready to go packages, offered by Holly and others (though, I suspect that the "others" are simply advertising the Holly product?). 

Input is greatly appreciated.

Has anyone used the Holley package?  Is there any benefit to using their product over a stock '87 parts swap? 




Offline VileZambonie

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Re: 1985 to 1987 Fuel tank & pump LS swap ... do myself or buy kit
« Reply #1 on: September 14, 2018, 04:05:06 PM »
I would only run in tank pumps, replace the hoses with pressure rated hoses and the selector valve. EFI rated clamps are a must as well. If you don't want to change the tanks, just keep the fuel level over 1/4 full.

You can also make your own baffle similar to modern style sending units that are part of the in tank assembly

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Offline 75gmck25

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Re: 1985 to 1987 Fuel tank & pump LS swap ... do myself or buy kit
« Reply #2 on: September 19, 2018, 07:10:16 AM »
The Holley sells their hydramat "fuel mat" that is supposed to work like an in-tank baffle to keep the pump supplied if you use your existing tnak.  However, I don't know anyone who actually has one.  It also costs in the range of about $150, so its not a cheap option.  I think you could buy an '87 tank with a baffle for about $150. In any case, you still need to buy the in tank pump also.

Another option is to install an external sump or surge tank, which is usually about 1-2 quarts in size, and it both holds the high pressure pump and serves as an external sump for your current tank.  There are off-the-shelf solutions, like the FiTech Fuel Command Center, or you can buy an external surge tank for about $50 and build your own.   The FiTEch product also gets pretty bad reviews on Summit, although they supposed have a newer model that works better.

This is another alternative to an OEM FI tank.  http://www.tanksinc.com/index.cfm/page/ptype=product/product_id=561/category_id=144/mode=prod/prd561.htm  Most folks seem very happy with them.

Bruce
« Last Edit: September 19, 2018, 07:28:01 AM by 75gmck25 »

Offline roundhouse

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Re: 1985 to 1987 Fuel tank & pump LS swap ... do myself or buy kit
« Reply #3 on: September 20, 2018, 12:58:31 PM »
I got a 87 tank from Rockauto for under $100

Offline Irish_Alley

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Re: 1985 to 1987 Fuel tank & pump LS swap ... do myself or buy kit
« Reply #4 on: September 20, 2018, 01:26:20 PM »
RockAuto Rant good luck if you have to return anything to them
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline roundhouse

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Re: 1985 to 1987 Fuel tank & pump LS swap ... do myself or buy kit
« Reply #5 on: September 23, 2018, 05:52:15 PM »
RockAuto Rant good luck if you have to return anything to them
I agree

Don’t order anything from rockauto if it is a suspension part that wears out
Ball joints and stuff are cheap Chinese garbage
Or if you’re are positive it will fit your car
You will play heck getting your money back

The gas tank was fine though

Offline ehjorten

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Re: 1985 to 1987 Fuel tank & pump LS swap ... do myself or buy kit
« Reply #6 on: September 24, 2018, 08:42:55 AM »
I have never had an issue returning stuff to RockAuto.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6