1987 Fuel Sender Conversion for LSx Swap

[aggie91]

LS-K - That looks good. Probably the same amount of work as mine too. What's funny to me, is the part number you linked to Summit is the same part number on the Holley (Earl's) web site that lists them for 250 psi.

NorCalAnthony - They make a specific adapter fitting for the GM fuel lines on the rail. Between the tank and the rails I will be using braided line.

Here is the part numbers for the fuel rail adapter fittings:
Supply Line: http://www.summitracing.com/parts/rus-644120/overview/
Return Line: http://www.summitracing.com/parts/rus-644110/overview/

I used the black ones. 644123 (Supply) & 644113 (Return)

[NorCalAnthony]

Originally Posted by aggie91

NorCalAnthony - They make a specific adapter fitting for the GM fuel lines on the rail. Between the tank and the rails I will be using braided line.

Here is the part numbers for the fuel rail adapter fittings:
Supply Line: http://www.summitracing.com/parts/rus-644120/overview/
Return Line: http://www.summitracing.com/parts/rus-644110/overview/

I used the black ones. 644123 (Supply) & 644113 (Return)

Ok cool those are the same ones I've seen a few other people use. Out of curiosity, why didn't you use those on the sending unit instead of the compression style? I think the compression style looks like a more solid connection but wasn't sure if there was anything more to it than that...

[aggie91]

Originally Posted by NorCalAnthony

Ok cool those are the same ones I've seen a few other people use. Out of curiosity, why didn't you use those on the sending unit instead of the compression style? I think the compression style looks like a more solid connection but wasn't sure if there was anything more to it than that...

the sender has a different style of bead form on the end of the hard line. It is more of a bulge to hold a hose on with clamps. The LS rail has a squared lip/ring form that is further from the end of the line. I don't think they make an adapter for the type of bead form on the sending unit. Atleast I have never seen one...

Compare the 2nd picture in post #1 of the tubes on the sender to the tubes on the LS fuel rail and you will see the differences I am trying to explain.

[65standard]

This should be a sticky. Great information for LSx swappers.

My question is, do you really need to convert the return line into a high pressure line?

[65standard]

My truck already has the spectra GM11B tank. It does not have any baffle inside. Are you sure this tank is for EFI?

[65standard]

The spectra GM11C might be the 16 gallon EFI tank?

[aggie91]

Originally Posted by 65standard

My truck already has the spectra GM11B tank. It does not have any baffle inside. Are you sure this tank is for EFI?

Originally Posted by 65standard

The spectra GM11C might be the 16 gallon EFI tank?

I used the GM11B tank, it does not have a baffle in it, but I have not had any issues with it when the level gets low. I am not 100% sure that the GM11C has a baffle in it either. In a search I did this morning, the GM11C does come up as the tank for a 1987 R10 with TBI...

[aggie91]

Originally Posted by 65standard

This should be a sticky. Great information for LSx swappers.

My question is, do you really need to convert the return line into a high pressure line?

I converted mine to -6 AN for the simple reason that I was reusing some existing -6 AN lines for my fuel system. I am not sure what the actual pressure is in the return line (but should not be over 60psi), but on MY return style rails, I could only find the adapter for a -6 AN and it is just simple to change over the sending unit to -6AN fitting.

Most push lock hose and fittings are rated to at least 200psi and that could be a simple hose to make up with -6 JIC fittings (same as -6 AN fittings) that don't even use hose clamps. Having the -6 AN male to 5/16" tube fitting on the sending unit is just extra safety against a hose and clamp leaking.