Got a quick question and I think more people in this section would know the answer. Can you take a plastic fourth gen tank and put the thirdgen sending unit in itand it will seal up correctly? I dont want to have to re wire anything and just drop in the thirdgen wiring and pump.

 

No I dont think you can. The tank openings arent the same size for one, but not sure you could adapt the thirdgen sending unit to the 4th gen assembly/bucket.

The fix has been to use a sending unit from one of the early 90's GM cars that fits the 4th gen assembly, but has the correct ohms range for the 3rd gen gas gauge.

 

Or on the flip side, modify the factory gauge to work with the fourthgen sender. De-solder two resistors and replace them with another ohm rating. I can't say I remember it being done on Camaros, just Firebirds. But one, I have a horrid memory, and two I don't see why it wouldn't work on a Camaro cluster.

 

Got any specific models to get one like that?

As for the original question.....It can be done. Recently a guy has done it here on TGO but I don't recall which thread.

 

That was the other way around, a 4th gen pickup (a 6.0 liter pickup, if memory serves) in a 3rd gen tank.

 

Nope. I was right & found it with a Search. Post #5 shows it.....Post #14 is his Reply confirming it.
https://www.thirdgen.org/forums/engi...astic-gas.html

 

I know it won't fit a 97 metal gas tank as the sending unit uses like like 6 nuts to hold it in place. Not sure if a LT1 tank is like that but that is how my 3.8 is.

 

Now I know why I didn't remember it...

 

I'm not particularly fond of burning up in a car fire, so I will stay away from the screw & caulking approach.
Not meaning to hamper anyones creativity, but RTV is not meant for immersion in gasoline.

Orr89RocZ, I should have built you one of those instead...

 

Yep that likely would have been quick and easy

I dont know the part numbers as i had Lonnie put together my fuel system. Look him up for your needs. I got twin pumps and my gauge works great

 

I sourced out a new third gen tank at a local radiator shop, so all is well now. The tank that was in my dad's purple haze convertible had a leak and was all corroded inside when we pulled it to put a Walbro pump in it.

 

Not sure what the cause or source of the leak was on yours, but I do know that their was a factory recall on our tanks that affected the 89-92s. There was a problem with the filler neck developing pin holes where it met the tank. I know this because I had mine replaced under the recall program. The problem with the process is there were no OE tanks in the system anymore ( Summer 2009) I ended up getting an aftermarket replacement at GM's cost. It was a bear to get them to make a decision. Keep in mind that was when they were going through the bailout/bankruptcy issue, so that could ve been why it took them so long to decide.( about a month) Took me calling up to District Managers to keep the ball rolling... Jus saying

 

I will look into that. thanks!