I really don't want this in my car any longer. Early '79 was the last "year" for stainless expansion tanks. Black from factory. Can be re painted or stripped and polished. No rust, no leaking bungs, no dents, no issues. Buy it!
All the 74s I saw back then including mine were plain steel painted black. They were particularly prone to developing pinholes, mostly above the water line. I had to start patching mine with sheet metal screws and silicone when the car was a couple years old. It finally got to the point where I had quite a screw collection on the tank. Shortly after they introduced the plastic tank, I got one.I think only '74 was stainless. My original '75 was steel (and rust).
All the 74s I saw back then including mine were plain steel painted black. They were particularly prone to developing pinholes, mostly above the water line. I had to start patching mine with sheet metal screws and silicone when the car was a couple years old. It finally got to the point where I had quite a screw collection on the tank. Shortly after they introduced the plastic tank, I got one.
I'm nearly positive the '78 left overs were put on early 79s and probably all through 79, until they ran out of stock. All painted black. My 79 was built mid/late-mid 78. I'm pretty sure is stainless, even if its not stainless, its not rusting anywhere, inside or out, and someone should buy it.From what I recall there was only one year they were actually stainless, I think 1978 ?? The others were plain steel, which I believe was all of the painted ones - SS ones were not painted. Perhaps someone has more details, but that's what I've always thought.
Easy enough to check whether it's stainless---try a magnet. Most varieties of stainless will not attract a magnet, or only very weakly attract a magnet.