the first vapor tanks in 240z's (after the 'earliest z's which didin't have a vapor tank at all) were first made of plastic and were slightly different in size than the later metal vapor tanks. The interior panel that covered them was different than the later interior panels that covered the metal vapor tanks as well.

The fuel vapor tank on my 71 is plastic.

I hear that the steel ones hold up better, but mine is original (so far as I know) and not cracked, so I replaced all of the vent and overflow hoses this winter.

It doesn't weigh much, and I need the vent anyway.

Do you think there might be a vapor tank replacement made of HDPE that will last? Maybe not the exact Ysame size & shape. your oem plastic tank must be reaady to disintegrate if it's like the rest of the plastic on that car.