lukn4trbl355

iTrader: (2)

Wix-33737

Wolftrk99

iTrader: (5)

Heres what i did with vette fuel filter on mine!! Granted its a l92 intake but fuel rail shoukd be about same as far as modifying returnless intake to return system

Matthew Wiebe

Gbrown1320

iTrader: (6)

I've got an FAQ link online for the TBSS intakes. It may be useful for some of the questions you may have.

TBSS Intake FAQ

slow_white6.0

I have a 2003 GMC Sierra 1500HD that i decided to do the TBSS intake swap on. After looking through dozens of forum threads I didn’t see many people talk about adding flex fuel sensors with these swaps. So I just wanted to add to this thread with another way to adapt the c5 filter regulator and add flex fuel capability. I wanted to make it work as seamlessly as possible so I chose to go with the TBSS flex fuel sensor kit from Dedicated Motorsports. This kit eliminated the need to bend the fuel line, added an inline Flex fuel sensor and allowed me to adapt the filter regulator without it pushing the fuel lines into the firewall. Now I’m sure I’m not the first person to have thought of this, I just wanted to show anyone wanting to do the swap who may not have thought about it yet.

Mattt

Thanks for maintaining this great thread with info and pics on doing this conversion. The other thread I had seen on this conversion at GMFS is dead now that the pics are gone. I plan to convert to a NNBS intake on a lq9 6.0 that is going into a 2004 Tahoe, which was originally a 5.3 flex fuel engine (vin 8th digit Z). The 04 Tahoe Z engine has a return line. I see the Corvette filter/return/regulator is the typical way of dealing with this "problem."

Has anyone ever gone the route of just changing the fuel pump to a 05-06 fuel pump which has no return line? I am thinking an 05-06 Tahoe fuel pump should drop into my 04 tank and not have the provisions for the return line? Am I missing anything here with this line of thinking and it definitely will not work? This thought came into my head because I need to replace the fuel pump at the same time as the 6.0 going in, so why not kill two birds with one stone. The existing fuel pump works, but locks up if the vehicle sits for more than 4 days. It is the original and has over 300k on it, so it is time for a new pump. Would changing to the 05-06 pump accomplish the return line delete that I'm hoping for?

I have seen the fuel rail on the 05-06 Tahoe/Suburban and it is the square stock fuel rail like the NNBS/TBSS intake uses, and there is no return line on the square stock fuel rail.

If this works on the SUV, I don't see why it would not work on the Silverado trucks as well, changing over to the last iteration 05-06 fuel pump? Anyone BTDT?

Thank you in advance.

RedXray

Just finished a TBSS intake on my return fuel system Sierra. If the fuel tanks are the same I see no reason the returnless pump wouldn't work... I just don't know for sure.

What I do know is there are different TBSS/NNBS fuel rails that used different length injectors. The difference is in the length of the "cups" that hold the injector to the rail. You want the rails with the long cups for the short (47.4mm) truck injectors. Some TBSS trucks use the longer (53mm) LS2 injectors and fuel rails with the shorter cups.

Another difference is the NNBS rectangular port intake rails have the rail mounting tabs on the opposite side so they will not fit the TBSS cathedral intakes, they look the same except for the mounting tabs. Another thing to look out for is the new (superseded part number) GM rails do not have the schrader valve for checking fuel pressure. Not that big of a deal but if you decide to do a wet nitrous shot in the future you'll have to adapt somewhere else into the fuel system.

For your truck you will need an earlier 2008 and under intake part number (12580420). The 2009+ TBSS intakes use a different MAP sensor size and mount. Also the newer 2009+ intakes do not have the PCV nipple on the intake.

EDIT TO ADD: Just re-read your post... if you are using the Flex Injectors they may be longer than the regular truck non flex injectors. In that case you'll need the short cup rails. Just something to verify before buying rails (see chart below for E85 injectors)

Here is my setup with the long cup rails (12660709). I used a Corvette fuel tank hose (25948212) to get the filter/regulator back off of the firewall.



Rails with short cups and long injectors



Injector lengths

jbanda45

have you or did you ever change this filter out i installed mine and now i need to change it and cant disconnect it because its so confined

adriver

iTrader: (1)

I picked up a new TBSS manifold to swap on my 02 with the return style. Everyone seems to like their look after adding the ($130) fuel rails, + ($50) C5 filter to convert it, but I'm cheaper than that. I think I can accomplish this for much less than $180, and hoping you can help me with some ideas. As far as I know, the only problem with the 99-03 factory injectors and rails being used on the TBSS intake swap, is the crossover rail doesn't fit. I am trying to figure out what options there are, to modify the original return-style fuel rail's crossover rail, so I can use my original injectors and rails, to work on the NNBS intake swap.

I'm trying to come up with ideas on how to fix/change/redo/modify the crossover pipe. So far my ideas were:
Cut the rail -
1. Use hose clamps and 250psi push lock fuel line to connect it. - Could flare the ends after the are cut to help secure it, but AFAIK, that would be unnecessary.
2. Use tube adapter AN fittings, and hose. (Can add a tee-fitting in line to add a schrader valve)
3. and just have a "patch piece" (or 2) welded in place to extend it.

Buy a hose bender/flare kit for a hard pipe - ($30 on Amazon)
4. Put another bend or two in the factory crossover rail to give enough room to clear. (I have a spare just in case), avoid the original bends. I think I can get enough distance out of it.
5. Try to bend a fresh aluminum pipe. Flare out the ends, but not sure how to make it grip down on the end. Would have to make either two or three piece to include a schrader valve, and the return.

Make a fresh crossover soft pipe -
6. I have to measure it, but I thought I read 5/16". I could flare the end of this if needed. This might be the exact end I need. If these ends worked, I could make the crossover a hard or soft line. (I might buy one just to see).
LSX Innovations 6AN3125EFIM LSX Innovations Fuel Rail Adapter Fittings | Summit Racing

The same company ( ICT Billet LS Swap Guide for Gen III & Gen IV ) that sells the TBSS manifold and associated parts, along with quite a bit of other LS swap goodies and contributes plenty of helpful info, also sells: for "fuel rail hose GM LS1" to Barb and AN
ICT Billet AN817-01-05BA ICT Billet Quick Disconnect Adapter Fittings | Summit Racing
ICT Billet AN817-01-60R ICT Billet Quick Disconnect Adapter Fittings | Summit Racing
(This last option is my favorite so far). If I had to do it right now: I would use two fittings for the ends. Use a soft line with a Tee in the middle for a Schrader valve, and create a bracket to secure it up top. I could use push lock with the barbs, and might find some kind of heat shielding tube or wrap just for the heck of it, or use the AN fittings with a better hose (ptfe, or stainless). I think for cheap and easy, I would just get the barb fitting and push lock.

I think you see where I'm going. Honestly, I'm thinking someone can come up with a better idea than this. In this thread, I've only seen one person modify the crossover. Has anyone else done this? Are there any of these or other methods I definitely don't want to do, or is there a clear winner I'm not seeing?

arthursc2

iTrader: (5)

Factory NBS crossover is 1/2" and stainless. I've done this 2 ways already

1 was to remanufacture the crossover and weld it to the rails by cutting off the original crossover and leaving ~1" "nubs". Was a pretty easy piece, no compound bends, everything was in plane and the OE material welds really nice. I used .035 309 filler and tig

2 was to cut off the crossover, weld -6 bungs to the nubs and make a soft crossover. Again used .035 309 filler with some "stainless" weld bungs. Cross over was a 14 or 16" piece the customer supplied. Worked ok, I could have done better with more customer budget

both worked fine

I DO NOT suggest anything less than AN (37 degree) flares, or sufficient welding. This is fuel we are talking about. Fuel on top of a hot engine, with lots of exposed hot parts. Gasoline vapor ignites under 100F, let's be smart. Don't burn your truck down to save $200, at most

if you have or can get the tools, AN is the same as JIC. Tube nuts, ferrules and unions are cheap AF. The flaring tool and bender will be your biggest expense. I would not try to pinch a penny here. Brakes, fuel and oil are fluids/ systems not to be taken for granted