LS Swap. Inside OEM fuel tank? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**georgieb51** · 08-28-2025, 01:21 PM

I am putting an LS 6.0 2008 truck engine in my 70 K10 SWB and I already have the truck painted with the bed back on, and was wondering if anyone uses the original style fuel tank that went in the cab? I was trying to figure out where to buy a new interior tank from when I realized that folks are having problems finding a new interior fuel tank that works and fits. My original is proably good enough to use since it worked fine before restoring the truck SO I would really like to use the insiie tank Are there reasons why I do not see folks usIng this tank in their LS swap? Thanks

**57taskforce** · 08-28-2025, 02:41 PM

It can be done with an inline pump on the frame for sure. Walbro makes a few that work. The walbro 255 comes to mind off the top of my head, they flow a peak of 255 lph at 60 psi if I’m not mistaken.

Plus side is it’s easy to change, down side is that you’ll probably have to change them more often than the in tank style. Personally the in cab tank has never really bothered me much. Mine has all new rubber soft lines and grommet and I don’t get any gas smells that a lot of people complain about. If I get in a crash and it catches fire… well I guess the good lord is calling me home….im really not concerned much with that aspect of it honestly.

**LockDoc** · 08-28-2025, 03:30 PM

-
I put my LS pump inside the stock tank on my Dually build.

https://67-72chevytrucks.com/vboard/...=829820&page=6

Post #146 and #150.

I had to enlarge the sender hole a little on one side to get it in. So far it is working good. The downside for some might be that it is pretty noisy. My hearing is bad so it doesn't sound very loud to me but others have mentioned it.

If I was doing it again I would probably mount a Walbro, like 57taskforce mentioned, on the frame rail. I have one of those on my '67 Panel Truck with an LS1 and it has been working good for 8 or 10 years.
.

LS short box · 08-28-2025, 04:30 PM

I done a number of LS swaps over the years. I've used the Bosch 044 external fuel pump and C5 FFR combo on a number of swaps.
Worked well. Never a failure. You need to figure out a return line port back into the gas tank.
You could hear the 044 on start up and at stop lights but not driving down the road.

08-28-2025, 02:41 PM	#2
57taskforce All about them K’s Join Date: Jun 2014 Location: Land of Entrapment Posts: 6,979	Re: LS Swap. Inside OEM fuel tank? It can be done with an inline pump on the frame for sure. Walbro makes a few that work. The walbro 255 comes to mind off the top of my head, they flow a peak of 255 lph at 60 psi if I’m not mistaken. Plus side is it’s easy to change, down side is that you’ll probably have to change them more often than the in tank style. Personally the in cab tank has never really bothered me much. Mine has all new rubber soft lines and grommet and I don’t get any gas smells that a lot of people complain about. If I get in a crash and it catches fire… well I guess the good lord is calling me home….im really not concerned much with that aspect of it honestly. __________________ Tyler '57 3100 http://67-72chevytrucks.com/vboard/s...d.php?t=813888 '72 K20 Cheyenne: 5” lift, 35’s, front dana 60 blah blah blah… http://67-72chevytrucks.com/vboard/s...d.php?t=662879 ‘69 K10 SWB: 4” lift 33”s… in a million pieces http://67-72chevytrucks.com/vboard/s...d.php?t=805206 '98 Silverado LT K2500HD ECLB Vortec 454/4l80E: 6" lift 35x12.5x20’s Last edited by 57taskforce; 08-28-2025 at 02:50 PM.

08-28-2025, 03:30 PM	#3
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 26,743	Re: LS Swap. Inside OEM fuel tank? - I put my LS pump inside the stock tank on my Dually build. https://67-72chevytrucks.com/vboard/...=829820&page=6 Post #146 and #150. I had to enlarge the sender hole a little on one side to get it in. So far it is working good. The downside for some might be that it is pretty noisy. My hearing is bad so it doesn't sound very loud to me but others have mentioned it. If I was doing it again I would probably mount a Walbro, like 57taskforce mentioned, on the frame rail. I have one of those on my '67 Panel Truck with an LS1 and it has been working good for 8 or 10 years. . __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 -

08-28-2025, 04:30 PM	#4
LS short box Registered User Join Date: Jun 2015 Location: Carlos MN Posts: 2,592	Re: LS Swap. Inside OEM fuel tank? I done a number of LS swaps over the years. I've used the Bosch 044 external fuel pump and C5 FFR combo on a number of swaps. Worked well. Never a failure. You need to figure out a return line port back into the gas tank. You could hear the 044 on start up and at stop lights but not driving down the road.

08-28-2025, 01:21 PM	#1
georgieb51 Registered User Join Date: Aug 2014 Location: cooperstown. ny Posts: 1,630	LS Swap. Inside OEM fuel tank? I am putting an LS 6.0 2008 truck engine in my 70 K10 SWB and I already have the truck painted with the bed back on, and was wondering if anyone uses the original style fuel tank that went in the cab? I was trying to figure out where to buy a new interior tank from when I realized that folks are having problems finding a new interior fuel tank that works and fits. My original is proably good enough to use since it worked fine before restoring the truck SO I would really like to use the insiie tank Are there reasons why I do not see folks usIng this tank in their LS swap? Thanks __________________ 1972 Chevy Custom Deluxe Highlander, owned 34 years. 1970 GMC Sierra Grande 2500, unrestored, original. 1970 Chevy K10 Short Wide-bed, working on restoration.. 1967 Chevy K10 Short Stepside, unrestored original. 1969 GMC CST (Longhorn) 396, buckets, unrestored. 1995 GMC K2500, 65,000 miles, 454.



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