Most books that i read say that a 74 has an 18 gallon tank, but the replacement tank i bought said 24 on the box. It is the same shape and size as the one i took off. I also used 16-17 gallons and still see a few inches at the bottom. Anybody know what size it really is? Also, should the original tank have what looks to me like a rhino lining?? thanks guys

In '78 the tank was enlarged to 24 gallons. Prior to that was about 18-19 gallons. I believe they were lined with a rubberized compound that could under some circumstances collapse.

If your replacement tank looks identical, it may be mismarked on the box. I don't think the later 24 gallon tanks are interchangeable due to the fastback redesign for the '78 model year.

the outside of the tank has some kind of coating on it, not the inside, i was confused. I'm sure the tank was original, but no sticker.

My 77 has a 13 gallon tankin it, and yes, that neoprene bladder can collapse. It happened to me.