When is it necessary to swap out the gas tank? There aren't any leaks or major dents as far as I can see. I'm wondering how far I should take this since I have the axle completely out of the way...

 

There really is no need to replace it unless its leaking, dented to hell, or the diaphragm inside is ruptured. Other than that i really don't think you need to replace it. Just spray some new undercoating or paint on it to make it look nicer and call it good.

 

The gas tank can look great but the inside can be rusted to hell. If the inside is full of crap, then it will all be transferred to the fuel filters and carb. I think I would rather have a new tank than deal with that. I would look at the inside before you decide to replace it or not. I wouldn't worry about doing it now. The gas tank replacement is a fairly easy task. Having the rear end out doens't really matter at all.

 

I agree. A dent doesn't really matter to it. I would worry more about rust on the inside messing up the fuel system than anything else. If you drive the car everyday, you are probably ok. If you have had it sitting up for a long time, you need to change it out. It's pretty inexpensive insurance. And it goes up through the trunk, so you don't have to do it while the rearend is out.

 

If you do decide to change it be aware that you can upgrade to a '70 22 gal. tank if you like for more mileage between fillups. Tank is the same dimensions/mounting, the top of the tank just comes up ~1-2" higher in the trunk, about level with the floor. You'll need to swap to a '70 sending unit for your gauge to read correctly and either use a '70 filler tube, bend the tank inlet tube slightly or mod your original filler neck to point down towards the '70 tank inlet. Whichever tank you get look for USA or Canada made, the quality is better and the drain hole comes in handy.
Jon

 

This is all great advice, thanks guys! It has been sitting idle in my garage for over 2 years now.... Will check this weekend

 

That's a good idea bout the bigger tank, didn't know about that.

 

There was a little rust, not a great amount. But I took the whole thing out anyway, going to order a new one.

 

That doesn't look too bad, I have seen much worse than that. I would still get a new one though, since they don't cost much.