fuel tank swap from newer silverado to 81 C10?

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vwnut8392

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Hi, im new here. i've been working on cobbling parts together to swap a 6.0L LS into my 81 C10 truck. just picked up a colorado 5 speed that was actually affordable today after a few months hunt, YAY!!! anyhow, i was thinking about fuel tanks as i know the original C10 tank in my truck will not work with EFI. i have my step brothers old 2000 silverado sitting here with the frame broken in half so its parts. i was wondering if it would be remotely possible to swap the 2000 silverado's fuel tank into my 81 C10? im no stranger to fabrication as i understand that would be involved. i just want to make sure that the tank from the 2000 truck will even remotely fit in place of the OEM 81 tank. also someone changed the bed on my truck at one point and it has two gas doors on both sides though it only uses the drivers side. dont really want to start ripping my step brothers truck all apart just to find out there are major constrains and i have to hack the the 81 up too much to make it work.
 

Drauka99

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I doubt it will fit. 87 C-10 fuel tank for the LS swap. Get an 87 sending unit to keep the fuel gauge, will need to step up to a larger fuel pump than the 87 used for the LS. I've pulled my fair share of fuel tanks over the years and the C-10 fuel tank bracketry is different from any I have ever dealt with. (I'm assuming your a short wheel base.)

TIPS: if you change the tank like I did, install the end closest to the fuel filler neck 1st, its really tight tolerances there, I installed the front end first and had to remove those bolts again to get the back side to line up. Also the 87 tank fill port is larger than the 81, so you will need a new fuel hose to connect it. mine was part number FNH169 from Spectra Premium.
 

SquareRoot

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Save yourself the headache. For under $200 (may have gone up since I did mine a few years ago) just buy a new tank and sending unit assembly for an 87 C10. It has the baffles and correct hanger. Add an EP 381 pump and be done with it. If you cobble junk together you will find yourself at the bottom of the rabbit hole. Carry on.
 

vwnut8392

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yes i definitely do not want to use the original 81 tank. last time i looked into a drop in replacement tank for EFI they wanted 650-700 for the tank. seems a bit insane for just a bare tank with a sending unit to me. i have a few fuel pumps at my disposal including walbro 255, bosch 044 and deatschwerks DW 300. so thats 1 255lph pump and 2 different 300lph pumps. thanks for the input though guys. i'll poke around and figure something out because 700 for a tank just isnt in the budget right now. i know where there is an 87 K15 blazer. maybe i'll go see what the state of its tank is and put it where the spare tire was than fab something to the original filler door.
 

Drauka99

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Like was said there are lots of options for bare tanks for less than $200 and they are new. I think mine was $160.
 

TotalyHucked

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yes i definitely do not want to use the original 81 tank. last time i looked into a drop in replacement tank for EFI they wanted 650-700 for the tank. seems a bit insane for just a bare tank with a sending unit to me. i have a few fuel pumps at my disposal including walbro 255, bosch 044 and deatschwerks DW 300. so thats 1 255lph pump and 2 different 300lph pumps. thanks for the input though guys. i'll poke around and figure something out because 700 for a tank just isnt in the budget right now. i know where there is an 87 K15 blazer. maybe i'll go see what the state of its tank is and put it where the spare tire was than fab something to the original filler door.
You must've been looking at Tanks Inc's setup or someone similar. OE parts don't run that much. I've got our AMD '87 tank in my '85 with our sender and a Walboro 255 in my truck. Works great.

16 gal for $95

20 gal for $95

Driver's side sender for $80

Pass side sender for $80
 

vwnut8392

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You must've been looking at Tanks Inc's setup or someone similar. OE parts don't run that much. I've got our AMD '87 tank in my '85 with our sender and a Walboro 255 in my truck. Works great.

16 gal for $95

20 gal for $95

Driver's side sender for $80

Pass side sender for $80
thank you very much for this! saved me a lot of money that i can put toward other things on this truck! next question, these tanks are ambidextrous in a sense meaning they can flip from side to side correct? do the tank straps flip as well? just curious because my bed does have fuel doors on both sides and it currently uses the drivers side one but i was thinking about switching everything to the passenger side one because well im a german car guy originally and all german cars have their fillers on the passenger side. you know, force of habbit when you go to get fuel and get completely annoyed when the filler is on the wrong side.
 

TotalyHucked

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thank you very much for this! saved me a lot of money that i can put toward other things on this truck! next question, these tanks are ambidextrous in a sense meaning they can flip from side to side correct? do the tank straps flip as well? just curious because my bed does have fuel doors on both sides and it currently uses the drivers side one but i was thinking about switching everything to the passenger side one because well im a german car guy originally and all german cars have their fillers on the passenger side. you know, force of habbit when you go to get fuel and get completely annoyed when the filler is on the wrong side.
Yep, tanks and straps are ambidextrous but the straps don't interchange front and rear. The sending units are also side specific, but a little trick is to swap them so you can have a little extra loop in fuel lines for ease of service in the future. So put a LH sender in the RH tank or visa versa.
 

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