for the next phase of my ls1 swap I'm thinking of replacing my old 3rd gen gas tank w/ a plastic LS1 type tank/sender unit, I already have a new walbro for the 3rd gen sender but I dont know if it will work in the ls1 sender unit.
does any one know if its been done, how does it work, whats needed for the swap & how hard it is to do?
Thanx

 

Moved this to the LTX and LSX sub-forum.

I believe this was recently discussed. The 3rd gen replacement pump should work in the 4th gen pick-up assy. Should come up on a of this sub-forum.

 

Pump should swap. My walbro actually came out of a 4th gen (new unused) and plugged right into my 3rd gen

To use the tank, the filler neck must be trimmed, fuel level sender changed to a 90 ohm unit, new fuel lines created to make up the distance from the sender to the stock lines

More work than its worth if you ask me

 

Yep. Need to trim the rubber hose filler neck that the 4th gens use and if you want the top fill cap assembly to be firmly mounted to the car, you have to make a little mount so the assembly can bolt to it. I just laid my cap in the factory hole and it works fine.

I ran new braided lines all the way to the front of the car. A good bit more money to do it this way but it worked out well. Fuel sender unit is a 90 ohm unit like said, you can get them out of some of the mid early 90's pontiac cars I believe. Lonniesperformance.com has them. He has complete fuel pump/wiring harness packages that would drop in and plug into factory wiring. Else you can just use a parts store to buy the sender.

Atleast with the 4th gen tank swap you can use the 4th gen EVAP system on the tank with the LS1 computer

 

I don't regret going the 4th gen LS1 tank route. Just a stock pump so far, haven't really had it out to see if it's going to be adequate. But the aforementioned vapor system built in (cleans up the engine compartment), and the fact that I started with a carb car, and the fact that I got the whole tank for less than a replacement pump alone all factored into that.

The next project, LS1/4L60E, will probably get a 3rd gen tank (already picked up an in-tank pick-up, but now need a pump).

 

A little off topic, but I have a metal tank from a 4th gen (all the yards I went to had holes punched in all the tanks, 3rd and 4th gen, but I found ONE that didnt). The pickup was all cut up and just a pile of junk. Would I be able to use my 3rd gen pickup in the 4th gen tank? And Id have to shorten the metal filler tube right? If it doesnt just bolt in, Ill just cut off the filler neck and use it to replace my screwed up stock one.