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I'm going to replace the Gas Tank (and hopefully find build sheet) since the car sat for years and has sediment in tank and bumper has disintegrated for easier access.
Please any advise on all aspects as far as best stock replacement tank.....I worry about aftermarket sending units since they are probably made in China.... I did see a complete kit with everything under $300
The advice I need is where I should get tank and best advice on removal and replacement....plus any "gotcha's" Its a 1974 BIG BLOCK...
I purchased my new tank from Holley.
It’s the original style for carbureted C3’s but they also sell the original style set up to use an EEI system with an in tank fuel pump.
They sell the fuel socks, sending units fuel pumps and everything else you may need for the fuel system.
Post us up some more photos of your 74!
Both Quanta tanks I have had new were excellent reproductions (made in Canada). As for the tank sender, the Corvette vendors sell them, and the one I bought works. Not sure where they are made. Otherwise its just gaskets, hardware and hoses. Maybe if your sender works, just replace the sock. If you can test the fuel seperator, and it functions properly, its probably better to keep the original than buy a new reproduction. GM simplified the fuel vent system greatly as the C3 generation continued past 74.
- Siphon fuel from tank
- Remove spare tire and housings, and both mufflers out of the way, which might require some of the exhaust disconnected upstream depending on what system is installed and how its connected. .
- I am not familiar with the 74 vent system on left side of tank, but they may use a plastic vapor seperator, so that side will need carefully disconnected at upper left side of tank
- Disconnect fuel supply and return hoses. I think in 74 they are still on bottom of tank at the sender (by77 they moved the sender to top of tank).
- There may be a grounding strap somewhere, not sure.
- Disconnect two tanks straps. Front clips into tank support crossmember, on the rear remove two bolts that attach straps to rear crossmember.
- Then remove four bolts (two on each side) that attach the tank support to the rear frame rails......and lower it all down to the ground.
- Before installing the tank sender, I would hook the wires up to it, and have someone move the float up and down and make sure it works. As far as accuracy, don't expect alot....its not modern stuff. When my tank is full, the gage indicates full, but as the fuel quantity decreases, its not very linear, and when gage approaches empty, there is still alot of fuel left. I typically operate like I do on the Road King and judge when I need gas more by how many miles I have accumulated. I guess some people spend time to verify the accuracy. Willcox Corvette has some good tech information on their website about accuracy and calibration....check that out.
I would not be too hopeful about finding a legible tank sticker. Both my 77 and 69 had around 60,000 miles on the cars. The 77 had a few words you could read, the 69 was barely identifiable as a piece of paper. .
Last edited by Shovels and Vettes; Jan 24, 2021 at 08:59 AM.
Not sure the condition of your original tank and it may need replacement, however, I was on a similar track when I changed course. I have a 82 and after removing fuel tank pump/sending unit found I could reach into the tank through the hole from sending unit/pump removal. After draining the old gas I was able to reach in and clean out the sediment and remains of a fuel sock left in the tank to get a good cleaning inside. Upon inspection I found the tank in good condition internally and externally appears fine also so I left it in.
If at all possible, reuse your original straps. Bending new ones to fit can be difficult.
On my 77, when I dropped the tank, the sending unit was good, so it is back in there and still working fine.
If for any reason you use the original tank, Eastwood sells a spray can paint that is meant to appear like the original finish. It really doesn't, but it would be a way to put uniform finish on the tank if there are any areas that you had to sand or ? to remove corrosion. BUT......the tanks are really inexpensive, and well made. I would change it.
Mine for my 73 came from Canada. Everything fit good. Quality product. Sorry I forget the brand
Recently replaced the tank on my 72. The tanks to buy are made by Spectra manufacturered in Canada. Mine was perfect replica of the original. No Anderson logo though. I believe the same part number GM33D fits your ‘74. Check application to be sure and google part number. Multiple sources sell this tank. I bought a new sending unit and all other related parts like anti rattle pads. Use spray adhesive on pads and apply the pads to the tank. They don’t move around when you reinstall the tank. I also used High Tack liquid sealant for the cork gasket from the tank to the filler neck. Suppose to withstand gas better than silicone. It’s not a bad job overall. Good luck.
Likely a sealed cap. Is your current cap sealed or vented? If you have a charcoal cannister evap type system (My 72 does located in drivers fender below PB booster works with fuel separator check valve on left side of tank) then I would say sealed cap I think 70 is last year for vented cap. A lot of parts vendor websites have incorrect info I have found. Double checking is wise.
Napa Auto parts sells both the vented and non vented caps for about $30.00.
They are manufactured by Stant who I believe was the manufacturer of the OEM caps.
The one I received from them was heavy steel, fit perfect and was a nice piece.
Replacing Gas Tank Advice
