I had a similar problem with my 79'.  Just started dripping gas in the driveway one day and I found it had rusted through at the straps.  When I did remove it to attempt a repair, I discovered that the metal part of the tank was extremely thin, almost like just a protector for the actual tank which was about 1/4" thick plastic, certainly not rubber.  I ended up finding another tank lcoally and replaced the original.  The replacement was the same type, with a heavy plastic liner covered by a thin sheet metal exterior.

Wil, I'm guessing by the date of your post you have taken care of the fuel tank replacement or problem?  I have to do this to my 78 vette also and was wondering what you ended up doing, if you replaced the tank-did you run into any problems, any tips you have (what worked/ didn't work, etc.). Any information would be greatly appreciated.  Also, what is the easiest way to tell if the tank is the problem or a hose or something.  Any info. about a good starting point, and run down on how to proceed from ruling out one problem to the next. Sorry about the length of the post-my husband and I are new "shark" owners and need any suggestions you all have. Thanks so much!

csharkgo, you can buy a new replacement tank for your '78 from Corvette Central for $249. It doesn't come with the internal 'bladder' however, so they recommend sealing the tank with POR-15.

Hope this helps solve your problem--and welcome to the site!

ECKLERS has a new tank for your car  search part # 50755. less than 275 dollars.

Thanks for all the information.  I found a  new 78 fuel tank (with some small dings but nothing major) for sale on this site under the parts for sale section for $100 plus shipping.  Said it would be a lot to ship since it's big and heavy.  Maybe I will check into this further.  Thanks for the responses though, and the research.  I appreciate it and it may come in handy!  Have any of you ever replaced a fuel tank previously?  Any problems encountered or advice which may come in handy?  I need all the help I can get. Thanks again!

Correction-the fuel tank was on a different forum.  Sorry-too much going on, and find myself not being able to keep up these days.

[QUOTE=csharkgo]Correction-the fuel tank was on a different forum.  Sorry-too much going on, and find myself not being able to keep up these days.[/QUOTE] .   Hey, don't feel bad, life is too busy for most of us to think straight. In my case, I think it's age,..... or limited brain capacity  (64 MB memory).

[QUOTE=wil_burkholder] <>Anyone know about solvents and sticky stuff?  I have my 78 fuel tank out and replacements are not available.  

Any ideas or suggestions?

[/QUOTE]

i have one suggestion for you. go to ecklers. they have replacement gas tanks for 249.99 that do not require the rubber bladders. hope this helps.