5.3L LM7 Swap into OBS

[97Yukon4dr]

Hey,
I'm going to be swapping the 5.7 in my '97 Yukon (4L60E and 4x4) with a 2002 5.3L LS over the winter.
I know there's a lot of mixed info out there, and I was wondering what others' experiences were, things they wish they had done instead, and overall just recommendations and quality parts I will need to purchase.
Anything is appreciated I'm just an apprentice learning and would like to do the whole thing on my own.

 

[MrPink]

Check out www.lt1swap.com/gmt400swap/

I am LS swapping as well as is @Wh4t3v3rs, @BruiserCruiser, and quite a few others.

I built my own harness for the engine/trans but have since changed my trans setup as I am going non electronic controlled trans. James(Wh4t3v3rs) went with a Holley Terminator to run his build, Bruiser went the same route I am and is sticking with a 0411 PCM, He had Brenden at Lt1swap.com tune out his VATS and other things to get the baseline for getting it running.

I am running ICT Billet mounts, Crank spacer, and a few other things of theirs. My route is a bit different as I am not using OEM gauges, No ABS, Air Bags, Vacuum booster(manual brakes), my truck will be N/A for a while with the BTR Truck Norris cam, but I will be turboing it eventually. I will be also learning to turn on my own truck, the biggest thing I can say is do your research! Also overbuild it when it comes to the fuel system. I am currently running a AC Delco EP381 pump with -6AN Fragola Push-Lok hose, Russel fittings and Oetiker clamps at all the fittings for safe measure. I will be stepping up to a 540LPH Bosch(www.efihardware.com/products/3123/bosch-motorsport-850-hp-submersible-fuel-pump) When I go Turbo/E85.

If you're not good with wiring there is plenty of companies that do plug and play harnesses. If you are on FB join the LS swapped 88-98 OBS Truck/SUV group and go through the files section, it has tons of info from people that have done the swap.

 

[97Yukon4dr]

Check out www.lt1swap.com/gmt400swap/

I am LS swapping as well as is @Wh4t3v3rs, @BruiserCruiser, and quite a few others.

I built my own harness for the engine/trans but have since changed my trans setup as I am going non electronic controlled trans. James(Wh4t3v3rs) went with a Holley Terminator to run his build, Bruiser went the same route I am and is sticking with a 0411 PCM, He had Brenden at Lt1swap.com tune out his VATS and other things to get the baseline for getting it running.

I am running ICT Billet mounts, Crank spacer, and a few other things of theirs. My route is a bit different as I am not using OEM gauges, No ABS, Air Bags, Vacuum booster(manual brakes), my truck will be N/A for a while with the BTR Truck Norris cam, but I will be turboing it eventually. I will be also learning to turn on my own truck, the biggest thing I can say is do your research! Also overbuild it when it comes to the fuel system. I am currently running a AC Delco EP381 pump with -6AN Fragola Push-Lok hose, Russel fittings and Oetiker clamps at all the fittings for safe measure. I will be stepping up to a 540LPH Bosch(www.efihardware.com/products/3123/bosch-motorsport-850-hp-submersible-fuel-pump) When I go Turbo/E85.

If you're not good with wiring there is plenty of companies that do plug and play harnesses. If you are on FB join the LS swapped 88-98 OBS Truck/SUV group and go through the files section, it has tons of info from people that have done the swap.

I was wondering about the fuel system. My in-tank pump is brand new as it had stopped working a week before my engine went. Am I able to leave that pump in the tank and just do an inline high-pressure pump with that of course running new fittings and lines

 

[MrPink]

You'll be fine for a stock LM7

 

[Wh4t3v3rs]

Hey,
I'm going to be swapping the 5.7 in my '97 Yukon (4L60E and 4x4) with a 2002 5.3L LS over the winter.
I know there's a lot of mixed info out there, and I was wondering what others' experiences were, things they wish they had done instead, and overall just recommendations and quality parts I will need to purchase.
Anything is appreciated I'm just an apprentice learning and would like to do the whole thing on my own.

I will answer any questions you throw my way. My truck is more on the "race truck" side, then the street side, but I have a little knowledge about a few rhings that might be helpful. The only advice I would really give is PLAN FOR THE FUTURE! If you think you might even for a second about a turbo, plan for that turbo!!! (Fuel system, exhaust, etc) if you're gonna run a shot of NOS next year, plant for that! It sucks doing **** twice. Be patient, do your homework and research, buy quality parts when needed (don't be a complete cheapskate!!), read other members build threads as they have alot of ideas, suggestions, and out loud thinking going on (great resources), don't be afraid to ask questions, but search search and search some more before you ask, and have a blast building it!!!

James

 

[MrPink]

^^^ THIS 100%.

I overbuilt my trucks replacement fuel system when it was still a TBI truck. I went with a AC Delco EP381 vortec fuel pump, -6AN Fragola Pushlok hose, Oetiker clamps at all my fittings(for extra insurance). But I will have to remove my bed here at some point to clean the frame up, and when I do that the truck will be getting a bigger fuel pump installed. Like James I hate doing things twice, but my fuel pump to me is the exception as I changed my build after I did it lol.

 

[0xDEADBEEF]

If you do a big revamp of the fuel system don't overlook the wiring to the pump. It might have been fine for a stock pump, but might not be for a pump with bigger current draw.

 

[Fishinfreak96]

Me personally, I would do the swap to get the truck running. If you delay putting something in because you "may" upgrade down the road, more than likely you won't finish your project. Get everything in and running before you go make major changes. It is good to research products and think about what you would like to do but if you don't need to change the motor, or fuel system or anything for that matter, I would wait until it is up and running.
This is a constant battle for me as I want to put an ls into my c1500 project. But I run into space issues doing all my stuff in my garage...etc. (all excuses)... Either way you do your project. it is good to have an idea of your plan but be flexible for change.

You can plan for an upgrade, but what is most important... Getting the job done and vehicle running or researching and buying products that you will need tuner help for or a dyno? Just my opinion.

 

[stutaeng]

Yeah, it really depends what the OP is doing with his truck and his budget. If it's just a daily driver and you are using the truck for running errands and hauling/towing stuff, not need to upgrade anything. Just drop the engine and go. You can spend as little as a few thousand to get back some really good life of your truck.

I did a low-oil pressure, worn out 4.3/4L60e swap to a 5.3/4L80e on my NBS 99 ECSB 2wd and just dropped in the engine; no mods whatsoever. I accidently burned up my swapped tranny, so I had to get another junkyard one. I'm rebuilding the first 4L80e as a learning experience, but even then I'm around $3k-ish, doing work myself in my backyard. I'm just a DIY'er (had never done an engine swap) and wanted a reliable truck for running around, hauling stuff for home projects, grocery shopping, hauling MTBs to the trails,... doing burnouts on my way to Starbucks, whatever. It's made the truck a lot more enjoyable to drive around.

I didn't really like this guy at the beginning, but I've grown to appreciate his simplicity and brutal honesty. Watch a few of his videos and you'll know what I mean. His videos are for LS swaps in general, but may help you out some:

xc_hide_links_from_guests_guests_error_hide_media

The thing about the LS platform is that you can spend as much or as little. There are no right or wrong ways, as long as you get to where you want within your budget. Get your engine adapter mounts, drop the engine and get the truck running, then upgrade as you go if you need the truck to get you around. A racing truck is obviously going to be a different scenario...

Good luck.

 

[Fishinfreak96]

The driveway engineer is a great source of free information. Couldn't agree more. Don't know him personally but see his logic and now I watch all of his videos just to gain knowledge.