73-87 gas tanks

[entropy454]

Anyone able to tell me if gas tanks are interchangeable for the years 73-87?
My 75 has a rotted gas tank and I was thinking of trying to get a gas tank from a newer model from a junk yard. Maybe a 87.
thanks
for the info

[iceman7329]

First off here in GA its illegal for a junkyard to sell you a used gas tank. Dont know about your state. Dont know about interchangeablety either.

[smokinn]

73-86 short had 16 gal
87 short box had 16 gal was either carb,gas, fuel injec or diesel
73-86 long box had 20 gal tanks in front of the rear axel
73-80 long box also had 25 gal tanks behind the rear axel
82-87 long box had 20 gal tanks

of course you have to make sure you use the correct filler inlet.

[72 CustomCamper]

Originally Posted by smokinn

73-86 short had 16 gal
87 short box had 16 gal was either carb,gas, fuel injec or diesel
73-86 long box had 20 gal tanks in front of the rear axel
73-80 long box also had 25 gal tanks behind the rear axel
82-87 long box had 20 gal tanks

of course you have to make sure you use the correct filler inlet.

That's not 100% accurate. Both my 86 and my dad's 84 long beds came factory with dual 16 gallon tanks. 73-81 has a smaller diameter fill neck than an 82-87. And 87 has a different tank as they were fuel injected...


Chuck

[smokinn]

Originally Posted by 72 CustomCamper

87 has a different tank as they were fuel injected...


Chuck

They might have been fuel injected but still use the same 20 gal tank as the others. They used the same tank all the way up to 91.

[ElGracho]

Originally Posted by smokinn

They might have been fuel injected but still use the same 20 gal tank as the others. They used the same tank all the way up to 91.

Wrong.

There are several different tanks for 73-87 trucks just like Chuck said.

73-80 trucks had 16 or 20 gallon tanks based on wheelbase. Longbeds got the bigger tanks because they would fit. Shortbed trucks got the smaller tanks because the longer 20 gallon tanks just won't fit.

From 81-86, long bed 1/2 ton trucks got the bigger tanks if they had a single tank and usually the smaller 16 gallon tanks if they had the optional second tank. They also made the filler necks larger in 82. 3/4, 1 ton and diesel longbeds got the bigger tanks no matter what. All shortbed trucks had one or two 16 gallon tanks.

For 1987, carburated gas trucks (I've seen this in a cab and chassis truck) and diesels used carryovers of the 81-86 tanks. The fuel injected gas trucks got new tanks with sumps built into the bottom. This was to prevent starving the in-tank electric fuel pumps for fuel when going up and down hills or around corners with a low fuel level in the tank.

73-87 GM pickups always had the saddle tanks from the factory. Blazers and suburbans were the ones that used the tank behind the rear axle.

[smokinn]

Then why can i open the parts book and find 87-91 use the same tank?

http://www.classicindustries.com/pdf...el&Exhaust.pdf

[72 CustomCamper]

Because like most people you didn't read it fully. It says 87-91 DIESEL...

[smokinn]

well duh. I must be the sleep deprived from the newborn.

[Captkaos]

The '87 - up EFI tanks (ALL Blazer, pickup, Burb...) had built in baffles in them to prevent fuel starvation. The electric pump was included/attached in the sending unit to provide pressure to the new EFI system.

[BBC Beater]

I used a tank out of a 75 or 78 in my 90 model 1 ton. Funny thing is the old truck in a junk yard was cleaner than mine lol. Also I used the pickup out of the old truck since my truck is changed to carb. It looked like the pickups were interchangeable too.

[Captkaos]

All sending units are interchangeble from 73-91 on the C/K R/V trucks.

[mikesz]

Originally Posted by Captkaos

All sending units are interchangeble from 73-91 on the C/K R/V trucks.

Fuel injected sending units are different than carburated sending units. Anyway the fuel tank part numbers for my carburated 85 C10 and for a fuel injected 87 R10 are the same according to AllData. I am converting to fuel injection and thought I was safe with the 85 tank but this baffle stuff keeps coming up. I really dont want to wait until I drop my tank to look inside. So do I need a new tank with baffles or does my tank have them?

Mike

[Captkaos]

Originally Posted by mikesz

Fuel injected sending units are different than carburated sending units.

Yes, they are different, what I was saying is that if you have a carbed tank and you want to use the EFI sending unit in the tank you can. I am converting to EFI (TPI) on my '78 Blazer and I won't be using a newer tank. Street and Performance has done a few of these truck this way and they indicated they are not having a problem with them. Your '85 tank won't have the baffles in them, only '87 up.

[mikesz]

Originally Posted by Captkaos

Yes, they are different, what I was saying is that if you have a carbed tank and you want to use the EFI sending unit in the tank you can. I am converting to EFI (TPI) on my '78 Blazer and I won't be using a newer tank. Street and Performance has done a few of these truck this way and they indicated they are not having a problem with them. Your '85 tank won't have the baffles in them, only '87 up.

When my gas gauge with stock carbureted sender shows empty it only takes me 14 gallons to fill my 16 gallon tank. That may have something to do with S&P not having problems. S&P does recommend the baffled tanks on their website though. I guess I will find out for myself. I still need to get a sending unit. Maybe I will try to get the tank with it.
Mike