dynamic88builder

looking to have a gas tank cleaned and sealed in CT has turned up with no luck. the local shops dont do it anymore. was told they arent allowed unless they buy some super expensive machine. i tried finding a new tank with zero luck. even tried a suggested GM37C tank (which is for a 66 Bel Air) and its about 8" too wide, not sure if its because i have a convertible or not and the tank is different size than a tank from a sedan. Honestly Im not sure inside my tank is even that bad i think my real problem was my fuel lines. my tank is out at the moment because i tried the GM37C (for sale by the way..Pm me) so im going to rinse some fuel through it and see what comes out if anything. maybe pull sending unit and see what it looks like in there. Should i search tanks by dimension? has anyone ever done a fuel cell in the trunk safely? open to suggestions

Vistabrat72

The exhaust pipes on the year Chevy you are speaking about follow outside the frame on the way to the back past the axle, if I remember correctly, they exit pointing down just behind and past the rear wheel(s). Pictures on the 'net show all sorts of options for tail pipes! One our large Oldsmobiles, the tailpipes go to the rear in between the frame and fuel tank, fairly tight to begin with. Unlike the A-bodies, which can be practically built out of a catalog, the B & C-body fans have to be resourceful and make other parts fit. Been there, done that. Measure how much room you have total to each side between the frame rails. If the Chevy tank looks the same shape, though they are more shallow then the Oldsmobile tank, you may be able to work something out, As a note, the tank on our 66 Ninety-Eight LS was fine, but we needed an exhaust including the muffler back. Restoring a classic automobile is very costly up in Canada due to the weak dollar, customs, you name it, so we looked around. $25 later (CDN!) we found a practically brand new exhaust of of an early 1980's Buick full size. It fit like a glove, but the tail pipe is outside of the frame rail, between the lower rear quarter panel and said frame.

If you are looking for dual exhaust that can be covered later, the point of my long reply is that us large Oldsmobile fans have to be crafty and resourceful. The pictures shown are during the stages of fixing up the car, and are anything but factory correct, but we are getting to thoroughly enjoy the car.


The 1980' Buick tailpipe fitment

cfair

I don’t know if this will help but here goes.

Let’s start with big car commonalities for reference: 65 & 66 big cars, meaning 88’s/Starfires/Jetstars/98’s (perhaps years beyond too) have a factory capacity of 25 gallons. Understanding GM, this implies that those tanks were all had the same dimensions and probably varied mainly in the length of the filler neck.

There were variations in 65-66 A/C vs. Non-AC cars, but this was to do with the presence or absence of a fuel return line to the tank. A/C cars got the return line. Non-A/C cars didn’t, but that pertained to the fuel gauge sender, not the tank itself. Or at least that’s what I’ve seen. Happy to be proven wrong.

Searching & Swapping
So, your search for a ‘66 88 tank is at least 65-66 88’s (plus maybe JetStars) as a starting point. If that fails, I’d get open minded about 65-66 98 tanks whose filler necks are probably slightly different due to a different bumper configuration. The 98 tank necks maybe longer or shorter than the 88’s, I don’t know. From what I recall, the 88’s & 98 tanks have different part numbers. I can’t comment on 67 & later, but they might just fit too. For lots of those big car parts, the cars didn’t change all that much until 1971. If it were me on those later (I.e. post ‘66) years, I’d start the research by the tank capacity and roll the dice from there. With luck you may wind up with a filler neck that’s technically a little to long, or too short, but still works o.k. on the road. Looks like you already know that the tank retention straps can accommodate a wide variety of tanks.

Spare Tank Story
About 3 months ago, my mechanic traced a persistent squeak in my ‘66 98 convertible to a broken 56 year old spot weld inside my fuel tank which allowed the vent pipe inside the tank to move on every bump. It drove me nuts for years. I didn’t really want to cut my tank up to fix a spot weld. I also had a line on a tank or 2 in CA, so I went to Turners Auto Wrecking in Fresno, CA and bought a used 65 98 tank. So I bought & carried a used, slightly dented tank back to Northern CA for about about 4 hours. The whole way it was off-gassing toxic god-knows-how-old-gas-fumes. I ran 4 hours at freeway speeds with 4 windows down just to keep from being asphyxiated. Noisy too. Then my mechanics got it boiled out & sealed. Then we didn’t use it because they figured out out to just have a shorter vent in my original tank that didn’t squeak. There are pictures here of the tank from about 8 weeks ago or so under my user name.

In the end, my guys fixed my original tank and my original is now great. So now I have a spare ‘66 98 tank. No, not an 88/Starfire tank. But if we were compare dimensions, there just might be a deal here that would work for both of us. I’m happy to keep a spare since I have 2 ‘66 big cars, but if it gets you back on the road, I’m happy to recapture the storage space too. Let’s say $250 + the ride. I’m not in the parts business, so please be a little patient, but I can part with it. This will surely be a pain in the *ss to ship.

Other Options
If you want another option, check in with Jess at Hess Brothers in Redding, or Red Bluff, CA. A few years back they had a couple of 65-66 88/Starfires/Jetstars that just might have the exact tank you’re looking for. Also check the Desert Valley and other AZ classic car boneyards, they sometimes mislabel their stock, but you may well turn up the tank you’re looking for.

Warm wishes & good luck

Chris

Charlie Jones

Here's some info from the Hollander Interchange Manual .
Fuel tank , Oldsmobile , 1966 all models except 98 , Toronado , or F-85 is number 558.
That would include all models of 88 and Starfire .
I look up #558 and it shows ; Olds 66 except 98 and Toronado

OLDSter Ralph

See if they can be helpful.
https://www.gastankrenu.com/gas-tank-renu-new-york/

Kensey

I put an A body gas tank on my 72 Delta 88. Few gallons smaller, but worked.

I made the mistake of cutting my OG tank straps to get the old one off. So the new A body straps were a little short. So try to save your OG straps.

jcdynamic88

I have a decent looking tank from a 66 dynamic 88 convert in ma