1987 Fuel Sender Conversion for LSx Swap

[solidaxel]

I used AN fittings also but I silver soldered steel AN fittings to both ends of the fuel system, 87 pick up tank and return fuel system

[lowrodderchev]

for you guys that used the 87 sending unit will any gauge work with it? I did this on my 75 blazer I need to replace the gauge but wasn't sure if I could just keep the 75 gauge or do I need to get a 87 gauge

[aggie91]

I am not 100% sure, but it should. I think that the 87 and 75 gauges use the same resistance range. I know that my 84 gauge worked with the 87 sender....

[solidaxel]

The 87 sender worked n my 78 also, the old one was busted for 20 years !

[lowrodderchev]

Originally Posted by solidaxel

The 87 sender worked n my 78 also, the old one was busted for 20 years !

so you were ok running a 78 gauge to a 87 sender? classic parts is having a 10% off sale I'm going to order a new gauge save me like $5 or $6

[72MARIO]

The Gm fuel gauges were all 0-90ohm till mid 1990s you shoud not have any problems with the fuel gauge

[solidaxel]

Originally Posted by lowrodderchev

so you were ok running a 78 gauge to a 87 sender? classic parts is having a 10% off sale I'm going to order a new gauge save me like $5 or $6

Well I haven't run out of gas yet!!

I no longer have to put gas in the truck every 100 miles

The LS gets better mileage, but now I do not have a speedometer, I like the fuel gauge better!

[lowrodderchev]

Originally Posted by solidaxel

Well I haven't run out of gas yet!!

I no longer have to put gas in the truck every 100 miles

The LS gets better mileage, but now I do not have a speedometer, I like the fuel gauge better!

LOL same boat but ive been using a GPS app on my phone. thanx for the help

[Joe69C10]

Bringing back an old tread! Great write up. This will help me alot. Question: You are using the corvette style filter w/ return that you can mount near the tank. I'm swapping a truck 5.3 with the return already on the truck intake.

Would I just use a regular filter that is not a return style? and run two long fuel lines from the intake? Since the truck intake has a regulator built in along with return.

[Jstock85]

this will definitely help me as well. Aggie91 did you ever find out if the purple went to the gauge and grey went to power or vise versa?

[aggie91]

Originally Posted by Joe69C10

Bringing back an old tread! Great write up. This will help me alot. Question: You are using the corvette style filter w/ return that you can mount near the tank. I'm swapping a truck 5.3 with the return already on the truck intake.

Would I just use a regular filter that is not a return style? and run two long fuel lines from the intake? Since the truck intake has a regulator built in along with return.

This was set up for the return style lines on the intake. I did not use the corvette style return filter.

I just ran two -6 lines from the tank up to the rails. One for supply and one for return. That set up worked with a pump upgrade to a Walbro 400 style pump and made over 515 ft lbs of torque before blowing a head gasket...

[aggie91]

Originally Posted by Jstock85

this will definitely help me as well. Aggie91 did you ever find out if the purple went to the gauge and grey went to power or vise versa?

Gray is power to the pump.

Purple is the sender wire to the gauge.

[Jstock85]

Cool. Thank you! Did you cut the plug off and solder wires?

[Jstock85]

Grey to the wire going to the fuel pump relay and purple to the fuel gauge?

Sorry meant to put that in the other post...

[aggie91]

Originally Posted by Jstock85

Grey to the wire going to the fuel pump relay and purple to the fuel gauge?

Sorry meant to put that in the other post...

Yes.

For the plug, I got the matting connector and pins and put that together on the wires going back up front to the cab area.

[Joe69C10]

Originally Posted by Jstock85

Grey to the wire going to the fuel pump relay and purple to the fuel gauge?

Sorry meant to put that in the other post...

Yes, purple to fuel sending unit for gauge and grey to power fuel pump. Purple is typically the sending wire color on alot of GM's.

I would look for the plug so you can just plug it into the fuel pump. My friend was able to buy one through Autozone I think?

[Jstock85]

Ill do that Joe. Thanks

[Jstock85]

Originally Posted by Joe69C10

Yes, purple to fuel sending unit for gauge and grey to power fuel pump. Purple is typically the sending wire color on alot of GM's.

I would look for the plug so you can just plug it into the fuel pump. My friend was able to buy one through Autozone I think?

Do you know where I could get that plug from? Brand? PN? What that plug is called? That sort of thing.

Thanks

[72GreenMonster]

Aggie91

Great post and thank you.
I will be running this exact setup
Questions all answered.
Everyone on this site contributes!

So Thanks Again

[aggie91]

You are more than welcome!

I will be doing this same thing again this summer on another '84. Only twist will be this one is running dual tanks, so I will need to update the selector valve and those hoses too.

[rodstored-72]

Aggie,
have you moved forward on the duel tanks yet? I am in the beginning process of the same thing. I am interested in how you might/did go about wiring for both tanks so the tanks are not going at the same time?
thanks in advance

[skyphix]

Originally Posted by Jstock85

Do you know where I could get that plug from? Brand? PN? What that plug is called? That sort of thing.

Thanks

Its a 2 pin weatherpack connector... Amazon has them. I'm also going to check my local parts stores for them.

[aggie91]

Originally Posted by rodstored-72

Aggie,
have you moved forward on the duel tanks yet? I am in the beginning process of the same thing. I am interested in how you might/did go about wiring for both tanks so the tanks are not going at the same time?
thanks in advance

Summer did not go as planned. Completed the LS swap and only did the one tank. I'm not sure when I will get to the other tank, but I will be posting pics and descriptions on Henry's build thread when I do.

for now, here is the best thread I have found on the subject:
http://67-72chevytrucks.com/vboard/s...d.php?t=754061


Info on the Pollak Selector Valve:
This is the selector valve:
http://products.pollakaftermarket.co...n-valve/42-159

Can handle up to 65psi fuel pressure.

This is the kit they offer that comes with the selector valve, a DPDT switch, the connector for the valve and a switch plate that has main & aux indications.

http://products.pollakaftermarket.co...n-valve/42-300

The link has another link to a installation sheet with a great diagram for installation. the factory wiring and dash switch can be used to control the valve also.

Another good thread starting on Post 129 with pictures of the valves and hoses:
http://67-72chevytrucks.com/vboard/s...=516817&page=6

[aggie91]

Originally Posted by Jstock85

Do you know where I could get that plug from? Brand? PN? What that plug is called? That sort of thing.

Thanks

Originally Posted by skyphix

Its a 2 pin weatherpack connector... Amazon has them. I'm also going to check my local parts stores for them.

Here is a kit with both the male and female connectors and terminals. I think I bought just what I needed from another place.

https://www.amazon.com/Delphi-Packar...905826&sr=8-36

[skyphix]

Originally Posted by aggie91

Here is a kit with both the male and female connectors and terminals. I think I bought just what I needed from another place.

https://www.amazon.com/Delphi-Packar...905826&sr=8-36

Yep - exactly those. I ended up ordering a set with pigtails so I don't have to worry about buying the special crimping tool or screwing up the crimp (my luck) by using a standard crimper. I got mine from Del-City - service has been good but shipping was a killer. Oh well.