And the award for the dirtiest fuel tank,,,,,,,,,,,,goes to me! Look at these pics y'all! I drained the bucket after each rinse. Think shaking a bunch of nuts will be enough to clean it up before using cleaner and sealer or should I actually sand blast the inside? I think I can make an adaptor for a sandblasting gun to reach in there.

Edited March 16Mar 16 by Wrongway

Nasty mate !!!!!

Too far gone for my tastes and I think, for a POR-15 urethane kit. It would take days of tumbling that tank with nuts, bolts, washers, log chain and railroad spikes inside to get it clean. The "Marine Clean" fluid and the phosphoric acid in the POR-15 fuel tank kit would do a remarkable but still incomplete job of cleaning the inside of the tank and the urethane would eventually delaminate.

Your time, money and efforts will be better spent measuring your current tank for height, width and length and for what extra area your car has around it. And what the arrangement is for the tank filler neck. Then go shopping online to see what the Tanks, Inc. people have to offer.

See if the tank below will fit. Its one inch deeper than stock - buy longer straps, very inexpensive. Its also a fuel injection tank but you can buy or make a block off plate for the tank if that does not suit you.

https://www.tanksinc.com/index.cfm/page/ptype=product/product_id=417/category_id=128/mode=prod/prd417.htm

Rick

I hear ya Rick, unfortunately a new tank isn't in the budget right now and the POR15 kit should be here in the next couple days. I loved your idea of tumbling, but I don't have anything big enough to strap this to. I'm thinking sand blasting or media blasting may be the only way to go.

=:-(

How much are they charging you for the sand blasting? How much does a POR-15 Automotive Tank Cleaning and Urethane Kit cost? The new tank or one similar to it only costs $315.00 at the Tanks Inc site above.

Rick

2 hours ago, B52bombardier1 said:

=:-(

How much are they charging you for the sand blasting? How much does a POR-15 Automotive Tank Cleaning and Urethane Kit cost? The new tank or one similar to it only costs $315.00 at the Tanks Inc site above.

Rick

chris at Auto city classics has them for $279

https://www.autocityclassic.com/passenger-cars-m/1961-1964-pontiac-passenger-cars-steel-gas-tank-ts25p/

Rick, that one that tanks inc are selling is for a A body car

Edited March 16Mar 16 by 64 kiwi boni

Isn't a Grand Prix an A-bodied car?? What do I know?

Rick

Sand blasting will be done by me, I bought the gun last year and only need the media $25 for 14lb aluminum oxide. The POR15 kit was $115, I ordered it a couple nights ago. It should be here in the morning.

6 minutes ago, B52bombardier1 said:

Isn't a Grand Prix an A-bodied car?? What do I know?

I believe it is a "B body" in 1963 bro.

1 hour ago, B52bombardier1 said:

Isn't a Grand Prix an A-bodied car?? What do I know?

Rick

B baby B

Speaks volumes as to the trouble you've been through the last year.

5 hours ago, JUSTA6 said:

Speaks volumes as to the trouble you've been through the last year.

Sure does

After a conversation about the condition of the tank with my wife she agreed with those of you that said to replace it. Although her "logic" was different, "honey its over 60 years old, I'm sure it's no good, justa buy a new one". If you want to try arguing with that logic go ahead, it's up to you. Myself, rather than argue I ordered a new gas tank from Auto City Classics, which of course needed the new gas tank pad and fuel sending unit, the rubbers for the straps and the straps needed new bolts. The tank rubbers came from Amazon a couple days later so no pics of them. Fairly sure we all know what rubbers look like. So everything got installed a couple days ago. The one concern I have is the filler tube was extremely hard to remove from the old tank. The O-ring looked new, so I reused it. Maybe it was so hard because of years of dirt and grim, but I was kind of expecting a pop or something telling me the filler neck was seated in the new tank. There was nothing, even after beating it in with a 2x4 and dead blow hammer. As if right now everything is installed and lined up properly, the set screw that holds the filler neck to the tank lines up and with the seal in place on the filler neck where it passes through to body nothing moves and it's all tight. But if I remove the set screw I can justa slide the filler neck out of the tank with little to no resistance. Is this ok or correct for a Pontiac?

On 3/16/2026 at 7:43 PM, 64 kiwi boni said:

chris at Auto city classics has them for $279

On a side note,

yep, not even close Kiwi. You know how we do brother!

Change that o ring wrongway ! Wayyy easier now than once you fill the tank with gas and find it leaks !

You will know when you fit a new o ring and lube it to slide in , how it has a nice little resistance , then you know it’s doing its job nicely 👍

What I love is Wrongway getting permission to spend money from the boss!

Dude I’m jealous!

8 hours ago, 64 kiwi boni said:

You will know when you fit a new o ring and lube it to slide in , how it has a nice little resistance , then you know it’s doing its job nicely 👍

Thanks bro, that's what I was thinking but wasn't sure. When I was beating on it, it felt like metal on metal. Like the end between the o ring and the end of the filler neck was hitting the last bump in the tanks neck. Like the it couldn't go in far enough for the o ring to get in the groove. I did soak that o ring in oil over night also. I'll take a look tomorrow as long as the rain stops.

Well I pulled the filler neck again to take a closer look at the O-ring. It is flat spotted on one side. Why I didn't think about this before I have no idea. I removed to O-ring and reinstalled the neck and drew a line where the filler neck and gas tank neck come together. Then stuck the filler neck into the old tank. The line on the neck matches up on both tanks. Where the O-ring is touching the side walls on the old tank it is not on the new tank. The only place I could find that O-ring was Ames Performance, but It is ordered. So, at this point every single part in the fuel system has been replaced except the straps hold the tank up and they were cleaned up and painted while they were off.

perrrrrrecft mate !!! you can sleep at night knowing its right

i hunted for that o ring and it was ames who had them .

but i bet its a generic gm o ring ...

13 hours ago, 64 kiwi boni said:

i hunted for that o ring and it was ames who had them .

but i bet its a generic gm o ring ...

Your probably right about that also Kiwi. Now, were always talking about shipping prices to Kiwi land, do you remember how much the total cost was? I paid $5.50 for the O ring and $13.00 USD shipping.

6 minutes ago, Wrongway said:

Your probably right about that also Kiwi. Now, were always talking about shipping prices to Kiwi land, do you remember how much the total cost was? I paid $5.50 for the O ring and $13.00 USD shipping.

my one came with other parts mate, so i cant say on the shipping

What a saga. This should be the last time you have to muck about with anything fuel related on that car. Interesting that your wife had the good sense to suggest a new tank whilst you were squirming about trying to get out of it cheaply! As it turns out, your new tank sounds very reasonably priced. The old one was truly disgusting. It looked like it had been full of water. I suppose 63 years of use will take it's toll...my body knows about that.

Anyway, I am eager to see what happens next. You might even start driving it!

On 4/10/2026 at 7:06 PM, Fitzy said:

Anyway, I am eager to see what happens next. You might even start driving it!

Nope, at this point I think I should've used the gas to light the car on fire instead of pouring it in the tank!

OK, so first thing is that seal on the filler tube did work kiwi, you were correct brother. With it installed I put 5 gallons of gas in her and turned on the power to check the pressure. I also bought a new fuel pressure gauge justa so there's no doubts after spiking the others. The fuel pressure is now at 5.5- 5.75 PSI. That's where it felt best at my foot. Hit the starter and she fired right up, warmed up and feels great. Then shut her off and she's back to dieseling!!!!! The longer you let her run and the warmer she gets the worse it is. Everything feels good, no backfires or popping, throttle is very responsive right up to the point of turning it off. So back to work on her today.

Justa ordered a new set of floats for the carb. Maybe the difference in weight between the two after soldering that one float is affecting it. I can't see that being the issue but for peace of mind and to check that off the list they should be here Thursday.

I didn't really expect the floats to solve the problem. The thought was to take my adjustments out of the equation. So, with the new floats installed she still dieseled for about 18 sec after turning off. I'm grasping at straws at this point. Edelbrock says if its fuel related it has to be fuel pressure or floats. We know the pressure is good and the floats are good. Every component in the fuel system is new. I don't think it's the timing again because she starts right up, engine runs smooth with no vibration and no backfires. While waiting on seals and seats a few weeks ago I cleaned the plugs, they were carbon fouled pretty bad. Maybe with everything we've been thru with fuel issues and timing issues there's excessive carbon build up in the engine? Again, I'm grasping at straws, but I think I'm going to trickle water down the carb tomorrow and "steam clean" the inside of the engine unless somebody has another idea.

Wow !! I have never had that happen !!

Do the water jobbie mate and certainly check your float levels

It’s getting fire from somewhere !

Do you have a pic of the dirty plugs ?

I also think you need to drive her !

Burn some fossil fuel !

Then see how she behaves