1987 Fuel Sender Conversion for LSx Swap

[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...

[foamypirate]

Originally Posted by aggie91

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...

GM11C should have a baffle in it. GM1C (the 20 gallon EFI tank) definitely does, here is a photo of my new Spectra Premium, pn GM1C:

[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.