Thanks for all help, hints and advice.
I got motivated today and just decided to drop tank now. Took only about 4 hours with draining tank, breaks, and clean up ... and being careful ...
Great directions here I found in other threads ... really simple ... valence came down no prob, rest easy peasy ...
Below are some pics of grommet and tank.
When I removed the filler neck ... it would move up and down with almost no force ... I could move it down and back with one hand like I was waving a pencil ... and after I dropped tank about 6 inches, it pulled out will very, very little force ... and take a look at what grommet looked like. And what's with the plumber tape? Is that normal?
I didn't muscle or force or twist it, just a little firmness and pop .. it was out. And that just about tore it in half .. and look how almost rotted it looks. And looking at outside of tank .... it has to be this grommet. In pic I did above, I had wiped the grommet ... but look at staining above it after removal ...
Someone mentioned if it was backwards .... in pic below with me holding it .... my hand is on part that was inside the tank (wider diameter than other end) ... is that backwards?
Also - someone asked about vent ... that was my first thought .... but its a 70 so only has filler neck vent (no other lines but one on sender up to pump - and its for sure not there .. that side is dry as bone all time) which dumps inside the rail right of tank ... no fuel was leak there.
I am getting grommet tomorrow .... anyone have pic of it properly installed in tank before putting filler neck in ...
Thanks everyone!
Oh ... btw .... I didn't wipe down or touch the tank in those pics ... I dropped it with wife working jack .,. then picked it up and walked it to porch to finish draining rest .... that's how new and clean it looks .... just stains around filler neck
PS .. for our friends up north .... label says tank was Made in Canada ... made my wife smile (she from Ontario) ....