[RotorHead]

In my 350 S10, I have a 20 gallon S10 Blazer gas tank installed. The tank is an original efi tank, I want to get a sending unit for a 84 S10 Blazer w/o efi. The tanks are the same dimensions and everything, but they have different part numbers. Does anyone know, if any, the differences between the 83-84 20 gallon tank and 85 - up 20 gallon tank?

[pepi]

Sender as in fuel gauge, should be the same GM is 90 ohm. Efi and non efi is more about fuel pump pressure.

[RotorHead]

My issue is, will the non efi sender lock into the tank like it's supposed to? I have an external pump and would like to use the 85 sender because it doesn't have the provisions for the submerged pump. The non-efi sender's supply tube goes to the bottom and has a strainer. I'm using an efi sender now but I have a piece of fuel line in the place of the pump and the resister is burnt, so my gauge doesn't work.since I'm going to replace my sender to fix my gauge, i'd like to use the sending unit from the non-efi. The only thing that made me think twice is the fact that the efi and non efi model blazers have different part numbers for the tanks, even though they both share the same dimensions. So what is different between the tanks? Please excuse my grammar, I'm typing and juggling a 3 month old at the same time.

[FmrStrtracer]

Not sure, but the EFI tank may have a baffle in it to control fuel slosh. If the older sending unit fits the mounting hole, go ahead and use it.

[LATECH]

Just take the original sender/pump out and braze an extension onto the tube in place of the fuel pump so it sucks from the bottom, be sure to test fit it for length so as to get her close to the bottom, then get a strainer for the carbed setup and slide it on the tube.double check the fit and you are done.
You can do it without the strainer if you like , just put the tube next to the bottom (leave 1/4 inch from the bottom for tank expansion) and be sure to cut the tube off at a 45 degree angle so it cant suck flat to the tank and cut off the fuel flow.Only difference is you will want to use a filter inline to catch the trash from the pump sucking off the bottom.The EFI filter allready on there should do nicely, just replace it when you do the job as it may be restricted some, wich could cause a delivery problem, remember it was used under pressure with the efi pump and changing it to filtering as fuel is now pulled through by vacuum it becomes more sensitive to blockage, just change it more than once in ten years , you will be fine.

You dont need to buy anything. Having the anti slosh baffle in the tank is a good thing so dont sweat the small stuff. Be sure and check the sender to make sure it works correctly as far as travel and resistance.

You could get a used sender at the u pull it yard for next to nothing, just take an ohmeter along to be sure and get a good one.

[RotorHead]

Got the 84-85 non efi fuel sender and it worked out ok. The sender fit in the tank and the lock ring was the same. I did run into some trouble hooking up my return. I have a holley blue pump with a bypass style holley regulator. The return has to be able to flow the same as the pressure side or the regulator doesn't work. There is a 5/16 port on the sender but underneath there was this little plastic check valve and that got in the way of the return so I had to remove the valve. After all this, everything was good. I just don't like how my return just sprays in above the fuel level. Aeration and static would be my two concerns, I'm going to try to fit a tube that goes straight down to the bottom of the tank. Then my return will be fluid to fluid.