Gas tank swap

[stingray72]

Ok, this has probably been covered but most of the threads I've found are for the filler locations and quite frankly I haven't gotten there yet.

Anyways.. I started cuttong off the spare tire crossmember last night and tried to test fit my tank (blazer tank from ****************). I noticed there are a few things that I don't know what they are? I've attached a stick drawing looking towards the front of the truck as if I were standing over the tank.

I've got a pretty good grasp on the filler neck and the sending unit hole but there is a couple of other openings I don't know what they're for. I assume maybe a vent or something

There's about a 1" neck next to teh filler neck.
and there are (2) 1/4" or so necks at the corner of the tank (top left and top right)

What are these for? (and forgive my crude drawing)

[stingray72]

ttt

[Rdub]

Try a search on tank.... within the last 2-4 months this exact same subject was discussed and there was a drawing similar to yours which identified every part on the tank and what it connects to, or at least what it connected to on that persons truck.

[bigdog69]

Those two small nipples go to the carbon canister up front.

[wibilly]

the 1"one by the filler tube is the vent for the filler tube it will attach to the top of your filler tube just below the cap to allow air to escape while filling

[stingray72]

Originally Posted by bigdog69

Those two small nipples go to the carbon canister up front.

Is the carbon cannister necessary? What is it's function and can I put on along the frame rail or something? Can I cap those nipples?

[project1971]

i am not running a carbon can myself and just made those vents. My filler neck is almost 90 degrees as it comes out in the corner of the bed and it fills better with those as vents then when closed off.

[stingray72]

Okay then.. On to my next question. This tank sits up higher than the frame rails. What are you guys doing to get the bed to clear? Do I have to cut that cross piece on the bed?

If I had known it would be this much of a PITA I would have just fixed the tank in the cab

[low'n slow]

I had to trim the cross member in order for my poly tank to fit.

[Chris4x4Gill2]

Originally Posted by Rdub

Try a search on tank.... within the last 2-4 months this exact same subject was discussed and there was a drawing similar to yours which identified every part on the tank and what it connects to, or at least what it connected to on that persons truck.

any idea where that thread might be? I have searched and havent been able to find it

[John Fabris]

You do have to trim the crossmember for the bed to allow the tank to fit. As for the tank, if you are not using the charcoal canister, you can close up the ports that you will not be using. You only need the fill one and the one right next to it for your air vent.
Here is a link to the blazer tank install in FAQ
http://67-72chevytrucks.com/vboard/s...ad.php?t=74876

[Rdub]

Originally Posted by Chris4x4Gill2

any idea where that thread might be? I have searched and havent been able to find it

I don't know how to do a link but, did a search on "tank openings" & found the thread.... I was wrong about the drawing, actually it's a photo of a tank with all the fittings from the top of the tank labled .... try "rear gas tank install help!!!" by cwilkie on 6/21/06

[wibilly]

when i cut my bed support for clearance i discovered that the wood floor suports slip inside the steele suports nicly. i welded them inside to bux mine where it was clearanced to regain the strength i lost by cutting for clearance of sending unit and filler tube