Dude, I just looked on Ebay and saw about a dozen combinations of Left, right or both along with all the cross over pipes. Keep your C5 all C5. I can't speak to a C6 tank but why take a risk when you can just get what you know will work:

https://www.ebay.com/itm/C5-Corvette...0AAOSwP1JbWlOV

 

2003.5-2004 C5 uses C6 style tanks/fuel pump etc. (I assume the OP knows this). Fuel pumps are the same and to the best of my knowledge the tanks are identical as well. I just finished fuel pump and fuel level sender replacement on my 2003.5. Used a fuel pump designed for a C6. I think the fuel level sender part number changed in 2007, probably due to a PCM change or something. Anyways, I would not hesitate to get a C6 tank.

 

 

 

How difficult was that? How many hours? Did you have to lower the transmission to get at the fuel tanks to disconnect every thing?

I need to replace the fuel sensors in both tanks. Still trying to wrap my head around how bad this is....

 

P Jensen,

It's pretty high on the difficulty level. Now that I've done it I could probably do it in 1/2, 1/3 the time, but that's how it always goes. Not as bad as clutch replacement on jackstands though. Took me all weekend, working several hours each day, but I like to take my time and make sure everything is done right. If you have an auto trans, apparently there is less space around the trans and dropping it is a good idea. I have a manual and did it all the the transaxle and even the X-pipe in place. I did disconnect the xpipe to exhaust connection so I could rotate the x pipes out of the way. Removing the X/H pipe is definitely a good idea though, I would have done it, but I was having a hard time pulling the slip fit connections off so I just pressed ahead with them still on.

You'll need some tall jackstands, I have some 6 ton ones and I show the car is about 21" off the ground at the jacking puck lift points... plenty of room to get the tanks out, if anything a little lower might have made it easier to reach the crossover tube. I found myself doing a half situp while grabbing and turning stuff a lot. A lift would help tremendously.

A good thread and instructions:

https://www.corvetteforum.com/forums...fuel-pump.html

https://www.lingenfelter.com/PDFdown...L710140105.pdf

Here's a fun fact though. I had P1433 and P0463 "fuel level sender voltage high" or something along those lines. Replaced the sending units.....still had empty gas gauge. Turns out the sending units were fine all along (old ones looked fine too, not too corroded or anything). It ended up being a bad ground/connection somewhere in the wiring harness between the sensors and the PCM. I reseated all the connections in the testing process and it magically started working. I think it was 8 plug harness connector right above the transxle that connects to both fuel tanks.

Not sure what your codes are, but it's also worth checking out these 2 guides to pin down what your exact issue is before you start digging too deep (if you haven't already). In my case it wasn't totally a wasted effort thankfully.... was upgrading the fuel pump at the same time.

http://www.racetronix.com/Manuals/RX...%20Voltage.pdf

http://www.racetronix.com/Manuals/C5...%20Voltage.pdf

Those 2 are for my specific codes... Racetronix may have more for other DTCs, but it has a good 'procedure' at the bottom to pinpoint what's going on.