98 K2500, 5.7 to 5.3

[Zukikev]

Hey everyone, I believe I have done a reasonable amount of research prior to posting, but I have some questions I'd like to clear up.

The 98 2500 I'm swapping into has a 5.7 and 4l80e.

Will I require a different flexplate or some sort of spacer? I read about this at S&P (here: http://www.hotrodlane.cc/PDFFILES/Lisa%20Tahoe.pdf )

The LM7 I'm swapping in is a drive by wire. Do I try to work with it or swap a throttle body from a 99-02 truck that is not drive by wire? (S&P write up says get gas pedal and tach module. I'm not sure if I kept these parts from the 03 I got the engine from)

Is a conversion header required? Or will the stock LM7 manifold fit? The Shoenfeld headers won't fit a 4x4 truck but the NITROUS headers will fit a 4x4 truck, is that correct?

I am assuming I won't have to move the transmission and transfercase in the 98. Is this what the conversion motor mount kits achieve?

I don't have a rad. Which is the best one to use, a 96-98 or a 99+? Is there a difference?

Edit* some of my questions were answered so I removed them as they weren't very strong tech

[Zukikev]

Update. Got my 6L flexplate, spacer and bolts. Got an 03 gas pedal. Got my harness modified at Nelson Performance. Got dirty dingo mounts.

I am likely going to notch my frame for the low passenger side AC mount. I can't find much information on this, but it seems easier than forking out for relocation brackets and different AC compressors. Still looking for information on how this will work if anyone has a source.

My engine has a 2 line type fuel rail. How do I connect the 5/16 and 3/8 lines from the truck to engine? Flare tool and unions?

[scarybowtie]

For the fuel lines go to oriellys and they have quick connects 5/16 and 3/8 that will snap right on your fuel rails. Then cut your factory metal lines wherever you like and just run fuel injection hose between. Double clamp it with the nice clamps that have the little bolt and nut, and the sleeve on the inside. Lol that's the best I can describe em right now

[bowtieguy79]

Another option you can do it what I did with my 79. I'm not sure how the fuel lines will be on your 98 but I'm guessing you can connect them one way or another.



3/8's
http://www.summitracing.com/parts/RUS-640850/
5/16's
http://www.summitracing.com/parts/RUS-640860/

Then get the things you need to make up some stainless steel braided lines like I did for my tank


You will need these for the hard fuel line from the tank.
3/8's
http://www.summitracing.com/parts/EAR-165006ERL/
5/16's
http://www.summitracing.com/parts/EAR-165056ERL/

and while I'm at it, you will needed a pair of these
http://www.summitracing.com/parts/RUS-610020/
and this
http://www.summitracing.com/parts/SUM-230603/

Been using this type of fuel line set up for all of the LS swaps I've been part of. No leaks yet

[Zukikev]

Thanks for the replies guys.

Engine is in and running. I haven't finished the wiring yet, and I'm also having some problems with the start circuit. Not sure what it is, but I think it might be the tranny range/mode switch. The start signal goes through this switch before going to the starter relay. The purple/white wire is the signal wire to the starter relay, and I'm not sure where the problem lies, but I know if I jump this wire (86 pole of starter relay) to a GROUND, it will trip the relay. I have always known relays to trip with 12v supplied to 86 rather than a ground, so I am a little confused. I might bypass the range switch and run the start circuit like a regular relay from now on.

For the fuel lines, I was going to just put some flares in the stock lines and run unions but instead I shelled out for the AN fittings. The fittings needed are 16mm x 1.5 o-ring fitting, 14mm x 1.5 o-ring fitting, a 3/8 LS fuel rail quick coupler, a 5/16 LS fuel rail quick coupler, four -6AN hose ends, and about 20 inches of -6 AN line.

I fired the truck tonight and after it cleaned up and stopped smoking it ran remarkably well, especially considering I had no o2 sensors or MAF connected. My 5.3 came from a rolled truck so it smoked pretty good at first.

I do have a few questions now about the wiring of C100.
What is ignition 3 and is it the same as ignition 3 voltage?


A few pics below. Much more detailed thread here at my local 4x4 site:
http://www.s4wda.com/index.php?topic=3368.0

[bowtieguy79]

are you speaking of C100 pin C and pin N? I had this same question on my 05 swap in the 94 K1500. I don't have these attached on my 94, but kind of wonder if they feed power from the in cab fuse block of the 05 back to the Heated circuit on the O2's?

Nice fuel lines btw