Ok, well first let me say that this is not a fun job at least I didn't think so.

I bought a new fuel rail and manifold so I could prefab a few things which made the job easier but, it's not a necessity.

This will be typed up assuming you have new fuel rails and a manifold to work with. If you're just reusing the stock rail then of course it will have to be taken off to work with.

The first thing you want to do is take the crossover tube out of the two fuel rail sides, you'll need a Torx T-20 bit to release the hold downs for the crossover tube. When the crossover tube is off put new injectors in the four corner spots in the fuel rails. Then install the fuel rails back in the manifold without the crossover tube. Next comes bending the crossover. This part is kinda subjective but, I have a few pics that will help give an idea of what needs to be done. I just bent the crossover until it looked like the injectors had even gaps from side to side and front to back where they went into the manifold. Basically you want the injectors centered up in the manifold hole. Here are some pics of how you'll have to bend the crossover.

This one is a top down view of the stock crossover.

Stock crossover tube

This one shows how high the stock crossover tube is off the manifold. It's about 7/8" high.

Stock crossover height

This one is a top down view of the crossover bent for the new injectors.
Bent crossover for new injectors

This one shows how high the bent crossover tube is off the manifold. It's about 1 3/4" high.

Bent crossover height for new injectors

To bend the crossover like that I just grabbed it on both sides by the ends that go into the fuel rails and SLOWLY squeezed it together with it bending in the middle at the top. That took care of it width ways but, the passenger side of it still needs to be pulled forward to reach the hole in the passenger side fuel rail since it now sits further forward. To do that I installed just the driverside of the crossover into the fuel rail and held it in the middle at the top of the manifold. While holding it you can SLOWLY pull the passenger side of the crossover around until it's where you need it. The best thing to do is bend it a little and test fit it then bend it some more and repeat until you think the injectors are pretty centered up in there openings. The crossover tube has to be pretty good too where it mounts to the fuel rails or the gaskets that seal it might end up leaking.

Once you get the crossover bent you'll need to take care of the bolt holes in the fuel rails. Since the LS1 style injectors are taller the bolt holes in the fuel rails will have to be reamed out so the bolts can line up with the intake manifold holes again. They're easy to do since the fuel rails are plastic. The only one that presents a problem is the rear one on the drivers side. There is a bracket that the bolt goes through that will also have to be reamed out and it is made of pretty thick metal. The best thing I had to do the job was a rat tail file which took a while to get the material removed. I don't have a pic of that bracket but, will get one to post. On the drivers side you'll have to ream them out towards the front and on the passengers side you'll have to ream them out towards the back. One other thing, get a good idea of where they need to be reamed and take the injectors out and set them aside while you remove the material. You don't want any stuff getting down in the injectors through any openings in the fuel rail.

Here is a pic of what you'll have to do.

Reamed out bolt hole

Alright once you get all that taken care of you can cut some spacers to put under the fuel rail mounting tabs since they are now about 5/8" above there old location. I cut my spacers out of 1/2" aluminum tubing and made them almost 5/8" long. I filed them down until they fit and allowed the fuel rails to be snugged down just a little bit when the bolts were tightened. The spacers ended up being around .610" tall. You don't need to be exact just leave a little bit(little bit ) of space in between the spacer and mounting tab so the injector is pushed down when the mounting bolt is tightened up.

Here is a pic of one of the spacers.

Spacer

If you're still thinking about doing this there's more.

Next you have to cut off the old fuel injector connectors and splice in LS1 style connectors. Snip the old injectors off close to the connector so you have some wire to work with out of the loom. You can get the LS1 style connectors from www.speartech.com with pigtails for pretty cheap, $4-$5ea. I got mine from a guy with an old harness laying around so that is why it looks dirty.

Here is a pic of the two side by side. The LS1 connector is on the left and the truck connector is on the right. The wire colors all matched up between the two connectors except for one on the passenger side. The connectors all share the same pink wire though so you can't get them messed up when splicing.

Connectors

Now all you have to do is start soldering and heatshrinking. I recommend putting a rag under the wires when you're soldering to keep any stray solder from dripping into the intake if you don't have the fuel rails sitting in yet.

Soldered wires

Heatshrinked splice

Here is a pic of the mismatched wires on the one passengerside connector but, as you can see it still shares the same pink wire as the old one had.

Mistmatched wire

You'll probably be drinking by this point too.

Once you get the connectors all soldered and sealed up tape any exposed wires with electrical tape and put any wires back in the loom that you may have taken out. Here is a pic of the passenger side retaped and loomed.

Passenger side finished.

When you finally go to reinstall all the bolts and get everything tightened down you'll need longer bolts to put in the fuel rails. They are 6*1mm bolts and you need new ones that are around 1.5" long. I also used a lock washer and flat washer. Here is a pic of the old and new bolts.

New vs. Old bolt

Once you get everything bolted back up just turn the ignition on so the fuel pump will prime and check for leaks. If you have any make sure the gaskets aren't pinched and rebend stuff if necessary.

Don't start the truck up until you adjust the injector flow rate to match whatever injector you put in. Then check with a scanning program to make sure everything is OK. I initially put in a big injector constant that should have matched my SVO 42# injectors but, had to scale it by 88% to get everything looking good. I don't know why it worked like that but, others have seen this also with the injector flow rate and BIG injectors.

If you have any questions about anything let me know and I'll try to help out.

I would budget all day to get this done. You don't want to rush and end up having to deal with a leak once you think you're finished.

That's all folks.

John

Extra Large pics are here http://hauln.net/LS1Tech/truck/injectors/large/

 

A+ write-up John, Thank you man! I was wondering where to get the injector harness wires from and how the wiring would be. I will send Speartech an e-mail. So why are YOU doing this? Probably for similar reasons as me I guess
Man I hope this doesn't kill my milage too badly.

 

Well, it looks like it might be while before these SOB's are tuned in. I'm almost thinking my pressure regulator is toasted. If I set the Ltrims to be 0 at idle they slowly increase as the MAP increases which might mean the fuel pressure isn't rising.

I can't even think about hitting WOT because the wideband quickly hits 16:1 and steady rises if I stay in it. This happens VERY quickly like the fuel pressure is dropping or something. I need to get my guage hooked up and check that out. If that's the problem then I think things will be fine with these injectors because they idle and drive fine at part throttle.

The only issues are the increasing ltrims and extremely lean problem in open loop at WOT.

I've tried the offset values that I was using in my car with the 42# SVO's and the stock truck offset. The car settings seemed to be a little nicer.

When I get the injector deal worked out I'll let you know why I'm doing this Ryan

John

PS - Thanks for the A+

 

hey John, so you have some secret project going on? whats up?

exactly what injectors did you get?

 

Is that really you or has someone stole your account? :p You should know a little bit about what I'm doing.

I'm using the 42# SVO injectors. They should be like 49# injectors at our base pressure.

 

, just messing, did you try just adjusitng your ltims till they are mostly negative and then adjusting the PE vs RPM? thats what i had to do with the 50's. seems like my ltrims had about a 15point range with those injectors. tuff to get it just right without the offset but that is what the ltrims are there for.

 

you made that harder than it should of been. Mine was easy and i did not do some things you did. But good work and you know everyone always has there own way.

 

One thing is it probably "reads" alot harder than it is. I did do things kinda of cautious though. I just didn't want to end up with any fuel leaks while driving down the road because I didn't take my time or something.

What things didn't you do? If there is an easier way to do some of the things necessary please post up for others thinking of doing this.

What injectors did you swap in and did you have any trouble dialing in the settings?

John

 

Ttt +2

 

Yeah what gives?! I though you were putting your truck back to stock. I suppose time will tell what you have up your sleeve. With injectors of that size I'd venture to guess something FI...