Gas tank difference 73-74 Satellite Charger

I have a question. I have a 74 satellite and need a fuel tank. In rock auto the fuel tanks are different between the 73 and 74 years and $100 more expensive in 74.

The cars are basically the same so I’m wondering why the difference? Emissions?

The parts numbers are the same for 73 chargers and satellite as well

Then in 74 there is a large hump on top of the 74 for both ?

I talked to a guy who’s using a 73 tank in his 74 but I’m curious on what’s different ? Any ideas

74 has the vapor recovery tank in the fuel tank thus the large hump up on top. 73 has a small external vapor tank up on the shock cross member.
You can use the 73 tank and get the small external vapor tank or do away with all together.

Thx. Kinda what I thought. Think I will save the money and ditch the system. Thx again

i noticed the tank description stated a lock ring kit was included.
has anyone took note if the lock ring was thinner than the factory part, or if the lock ring was correctly sized to the new tank ?

when I got my 74 Gas tank can't recall if lock ring was included ( 12 years of that ) , but I can say the problem with them is not the lock ring, but the welded ring to the tank which locks the lock ring. It bends as soon you tight up the lock ring. So needs to be made carefully.

i remember the problem, but i didn't remember if it was the lock ring, or the retainer on the tank.
i have a new stainless tank that came with a stainless lock ring, but i haven't installed it yet.
i will have to compare both the ring and the retainer on the new tank to the old one, and watch closely for anything starting to bend or leak when i install the new sending unit, which is also stainless.

Ive never had the new rings fit well with any of the new tanks Ive gotten over the years so I always reuse the old lock ring

I also reused the old lock ring but mostly because I preffer to keep Factory parts on my car as far they are useable than repros. I couln't notice a diff on size and shape between the repro lock ring and the original, but I didn't even tried. The problem for me was the reatiner ring welded on tank.

Maybe if I was to use the new one I was to find both would bend? LOL.

I didn't get any problem with leakage thought. In fact I had to remove the lock ring, get straightened back the retainer ring on tank, and install the lock ring back gently.