Fuel tank covernsion

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Yapay

Junior Member
Joined
Sep 29, 2018
Posts
20
Reaction score
7
Location
North Carolina
First Name
Christopher
Truck Year
1987
Truck Model
R10
Engine Size
350
Something that has me curious. I have an 87 R10 with 16 gallon saddle tanks. What would stop me from swapping in the 20 gallon tanks if everything was replaced at the same time? Meaning everything from the tanks all the way to the fuel lines to my throttle body.
 

Keith Seymore

Full Access Member
Joined
Jul 13, 2015
Posts
2,607
Reaction score
8,011
Location
Motor City
First Name
Keith Seymore
Truck Year
1987
Truck Model
R10
Engine Size
4.3L
If it is a long wheel base truck - you could do that.

If it is a short wheel base truck - you'd have to get creative to make the long tanks fit in a space the factory did not allow for.

K
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,017
Reaction score
1,808
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
I expect 16 gallon tanks would be fairly unusual in a LWB truck, but you never know.

However, assuming you have a LWB truck and the 20 gallon tanks will fit, make sure you get 87-91 TBI tanks that are baffled and set up for the EFI fuel pump.

Bruce
 

Yapay

Junior Member
Joined
Sep 29, 2018
Posts
20
Reaction score
7
Location
North Carolina
First Name
Christopher
Truck Year
1987
Truck Model
R10
Engine Size
350
If it is a long wheel base truck - you could do that.

If it is a short wheel base truck - you'd have to get creative to make the long tanks fit in a space the factory did not allow for.

K
It is a LWB truck and after looking more at it I'm fairly sure it'll work out. Wasn't sure if anyone else had "upgraded" and maybe ran into issues. Thanks for the reply!

I expect 16 gallon tanks would be fairly unusual in a LWB truck, but you never know.

However, assuming you have a LWB truck and the 20 gallon tanks will fit, make sure you get 87-91 TBI tanks that are baffled and set up for the EFI fuel pump.

Bruce
I ended up finding where it said vehicles under a certain GVWR only came with the 16 gallon tanks. Mine is under that, but since its a LWB it should be fine because it looks like the mounting points should be the same along the frame. I ended up going with a pair of Sectra tanks which should have the baffling.

I'll be posting on how it goes once I get everything shipped in and installed.
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,475
Reaction score
23,678
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
It is a LWB truck and after looking more at it I'm fairly sure it'll work out. Wasn't sure if anyone else had "upgraded" and maybe ran into issues. Thanks for the reply!


I ended up finding where it said vehicles under a certain GVWR only came with the 16 gallon tanks. Mine is under that, but since its a LWB it should be fine because it looks like the mounting points should be the same along the frame. I ended up going with a pair of Sectra tanks which should have the baffling.

I'll be posting on how it goes once I get everything shipped in and installed.
Where did you read about the gvwr and only 16 gal tanks? Id like to see the gvwr's
 

Yapay

Junior Member
Joined
Sep 29, 2018
Posts
20
Reaction score
7
Location
North Carolina
First Name
Christopher
Truck Year
1987
Truck Model
R10
Engine Size
350
Where did you read about the gvwr and only 16 gal tanks? Id like to see the gvwr's

When I bought the truck it didn’t come with an owners manual. So I looked one up and got it. I’ll post a picture of the page in my book talking about it.

You must be registered for see images attach


For trucks under a GVWR of 8600 it should be two 16 gallon tanks. While vehicles over that will have the 20 gallon ones. It probably means R 20-30 would have them for the larger motors. Technically speaking I believe my R10 would’ve only came with a 350 as the largest motor from the factory. Hopefully the picture comes out large enough.


Sent from my iPhone using Tapatalk
 

Yapay

Junior Member
Joined
Sep 29, 2018
Posts
20
Reaction score
7
Location
North Carolina
First Name
Christopher
Truck Year
1987
Truck Model
R10
Engine Size
350
For anyone still following or wondering I have an answer. Yes you can convert your 16 gallon tanks on a long bed to 20 gallon tanks. The longer answer is get the tanks in does require some creative problem solving. I don’t haven pictures at the moment but basically the front tank holder doesn’t completely line up with the stock drilled holes in the frame. The work around would be to drill holes into the new/old holder. Otherwise yeah you can convert them and there’s plenty of space for the larger tanks. I’ll post pictures when I replace the driver side next weekend.


Sent from my iPhone using Tapatalk
 

Yapay

Junior Member
Joined
Sep 29, 2018
Posts
20
Reaction score
7
Location
North Carolina
First Name
Christopher
Truck Year
1987
Truck Model
R10
Engine Size
350
So for the final answer. Yes you can convert from 16 to 20 gallon tanks on a long bed. There ended up being no issues with installing the holding brackets. At first the front bracket on my passenger side didn't line up, but that was due to me not having pushed it up all the way. Bit of a challenge and after about 12 hours its complete. I've got few pictures of what I did. Mostly to the fact that I was working at my dealership on Saturdays and was on a time limit. A word of warning though. If you get new lines like I did from Lines-to-go then you will need to pick up additional hose in 3/8, 5/16, and 1/4 for the portions to the fuel pumps. I ended up using about 2 feet for each side. Makes it much nicer to install or remove the tank with all the extra line. Overall not bad.
 

Latest posts

Forum statistics

Threads
41,847
Posts
903,382
Members
33,361
Latest member
iiixtremeiii
Top