5.7/NV3500 to '01 5.3/NV3500 OBS '95

[jeebalow]

Well this swap has been a long time coming. My 5.7 has 190K miles on it and still runs strong, but the fluctuating idle issue has not been resolved. And I am done throwing money at it and seeing my truck parked month after month.

I was talking to a buddy of mine and he just so happened to have a 5.3 with 100K laying around. Not only that, but he also needed some flooring done in his house. So after some discussion (and work), he had flooring and I have an engine.




The engine came with the water pump and harness/ecu, but no other accessories. Luckily, there was an 06 4.8L nearby for me to pull the accessories from. I pulled the alternator, power steering pump, AC Comp, Intake cover, efans & relays, and oil pan from the 4.8.

Now, here is the list of parts that I have gathered from reading and research on the web that applies to my swap (mostly from 91blkstpsd's 93 build):

4575 [4572] 1" Back [Stock] Transdapt Motor Mounts
EP-381 AC Delco In Tank Fuel Pump
640850 Russell 3/8 in. to -6 AN
640860 Russell 5/16 in. to -6 AN
EAR-9894DBHERL -6 AN to 14mm x 1.5 O-ring
FRA-491971-BL -6 AN to 16mm x 1.5 O-ring
SUM-220690B Hose Ends -6AN
SUM-G1001 18" -6 AN Stainless Steel Hose
NFW1050 4.8L Flywheel from Oreileys
6302-VSP43 Pilot bearing
1377C Throwout bearing
S&P 12mm x 3/8" pipe adapter for Coolant Sensor -NEED LINK
S&P 16mm x 1/8" pipe adapter for Oil Pressure Sensor - NEED LINK
1302LS1 Schoenfeld Headers
RXG7-FPKG Pump Power - Debating this one

This doesn't apply to my swap, just keeping it for completeness. These parts would be used in place of the russell adapter fittings above for adapting a RETURNLESS fuel supply going to the engine (newer engines will use this):
33737 Wix Fuel Filter/Regulator
DOR-800-121 3/8" female connector
DOR-800-120 5/16" female connector
DOR-800-155 3/8" x 12" double ended male connector

As of now I am planning on reworking the harness that came with the engine. I have yet to go through and see exactly what each connector is for and remove the unneeded ones (the harness is for a 4L60E). I need to do lots of reading on this.

I will be ordering parts very soon, if you see an error in what I have listed or something I am missing please let me know. I hope to get the 5.3 off the trailer and onto an engine stand soon so I can start cleaning it up and familiarizing myself with it.

I did see the EGR stuff on the 5.3 and read somewhere that the newer engines do not have EGR. Did GM do away with EGR when they began using AFM? I don't think the Schoenfeld headers have provisions for EGR, is there a block off plate I can purchase to go on the intake?

I will continue updating this thread as I progress and more question pop up.

[jeebalow]

Turns out I didn't have all the fittings I needed to connect the stock TBI fuel lines to the LM7 lines. Here is a list of the parts that were missing:
EAR-9894DBHERL -6 AN to 14mm x 1.5 O-ring
FRA-491971-BL -6 AN to 16mm x 1.5 O-ring
SUM-220690B Hose Ends -6AN
SUM-G1001 18" -6 AN Stainless Steel Hose

I will also update the OP.

The summit order came in yesterday:




And the Pilot Bearing from RockAuto:


Today the O'Reilly order came in:




I also dropped off the headers to be ceramic coated at Finishline Coating in Mailwaukie, Or. Their jet black coating has held up well on the shorty headers I have on the 5.7 so I went with that again. Just ordered the fuel fittings as well.

I got the harness off of the engine yesterday and cleared the way to start cleaning the engine off:




And the reason I needed another oil pan:


Can someone tell me what this random part on the engine is for? It has one bolt and is pinned at the other hole. The top lines up with the fuel rail.

[matt167]

This is something I'd like to do to my truck ( also a '95 5spd ), so I'll be watching. I actually had the chance to pull a complete 4.8 with a little over 100k miles ( rear ended truck ) for $125+ accessories and wiring, but going from a 5.0L to a 4.8 seemed like that was backwards, tho the 4.8L probably still is a better engine than the TBI 305 in all respects. I know it's over +100hp over the TBI 305.

[Chriscon7]

This is something I'd like to do to my truck ( also a '95 5spd ), so I'll be watching. I actually had the chance to pull a complete 4.8 with a little over 100k miles ( rear ended truck ) for $125+ accessories and wiring, but going from a 5.0L to a 4.8 seemed like that was backwards, tho the 4.8L probably still is a better engine than the TBI 305 in all respects. I know it's over +100hp over the TBI 305.

Well he's going from a 5.7 to a 5.3 hahaha so same situation pretty much.

[jeebalow]

This is something I'd like to do to my truck ( also a '95 5spd ), so I'll be watching. I actually had the chance to pull a complete 4.8 with a little over 100k miles ( rear ended truck ) for $125+ accessories and wiring, but going from a 5.0L to a 4.8 seemed like that was backwards, tho the 4.8L probably still is a better engine than the TBI 305 in all respects. I know it's over +100hp over the TBI 305.

I will try to document what I do as best as I can. Hopefully it will be useful to you.

Well he's going from a 5.7 to a 5.3 hahaha so same situation pretty much.

Yeah same situation with this -.4L swap. I'm hoping for around 150hp over what the 350 had. And I have the potential to go way bigger in the future.

[Chriscon7]

Those headers look awesome btw, how much were they if ya don't mind me asking?

[jeebalow]

Those headers look awesome btw, how much were they if ya don't mind me asking?

Not at all, there's a link to summit in the OP $269.99. They're getting ceramic coated right now. Should have them back in a couple weeks.

[Chriscon7]

Not at all, there's a link to summit in the OP $269.99. They're getting ceramic coated right now. Should have them back in a couple weeks.

Wow how did i miss that link

Well good luck with the swap, when do you plan on getting it all together?

[matt167]

I will try to document what I do as best as I can. Hopefully it will be useful to you.



Yeah same situation with this -.4L swap. I'm hoping for around 150hp over what the 350 had. And I have the potential to go way bigger in the future.

Thanks. My 305 still holds great oil pressure and has good power/ uses no oil, but being I'v decided this is a truck I'm going to keep, I can put a little money in it and have pretty much what I want, without signing a big loan.
I should have went after the 4.8, but the day I was in the yard, I was getting something completely different and didn't have the tools necessary to make the pull.

I normally sell vehicles off after 6 months to a year, but I'v had this truck almost 2 years now, and I know if I sell, I won't find another.. Good luck on the swap.

[matt167]

Well he's going from a 5.7 to a 5.3 hahaha so same situation pretty much.

Yep. I love the idea of a LS based engine in my truck, but everywhere you read, the 4.8 getting dogged on pretty bad cause there not 5.3's, so when I looked and saw the '00 1500 and saw " Vortec 4800 " under the hood, I was actually disappointed.. I was set on a 5.3 or 6.0 just about a year ago.. 5.0L still has good power and I find it adequate for what I do, but a little extra won't hurt and I'd be certain the 4.8L can get better MPG than I can get right now ( which is 19 MPG avg on a good long trip )

[Chriscon7]

Yep. I love the idea of a LS based engine in my truck, but everywhere you read, the 4.8 getting dogged on pretty bad cause there not 5.3's, so when I looked and saw the '00 1500 and saw " Vortec 4800 " under the hood, I was actually disappointed.. I was set on a 5.3 or 6.0 just about a year ago.. 5.0L still has good power and I find it adequate for what I do, but a little extra won't hurt and I'd be certain the 4.8L can get better MPG than I can get right now ( which is 19 MPG avg on a good long trip )

Yeah the 4.8L does get dogged alot. I have no real comparison though because i've never even driven a 5.3 or 6.0.

[1993Silverado]

SO how exactly does a buddy end up with a spare 5.3 laying around with a BIG hole in the oil pan? Just curious. I'm also sold on the ls based engine into my 94 ecss but will be this winter before I start. Keep up the pics. This should be a good build

[jeebalow]

They used the Yukon that this engine came out of to fix a Tahoe and well they didn't need the engine since they kept the tahoe's engine in the tahoe. Haha long story. I'll keep posting.

[jeebalow]

Ok so I haven't got much done except read into MAF sensors and harness wiring. I am thinking I will replace the water pump with the engine having 100K miles on it. Problem is there are 3 different part numbers that come up when I look up a 2001 5.3 Yukon (what the engine came out of) what the hell? These are the part number that come up all ACDelco: 252845, 251743, and 251714. Which one is it? And I take it FelPro Makes better gaskets that ACDelco?

I am going to also order the MAF (not with the engine) and IAC (it was broken). And the only other parts missing are the adapters for the coolant temp and oil pressure. I have to get going with the harness and removing the old engine. Hoping to have this done before starting my last year of school at the end of september.

[jeebalow]

Small update for today. I stripped most of the tape and wire loom from the harness and used masking tape to keep the shape of the harness. I am planning on cleaning the engine and spraying the valve covers and block with gloss black maybe the valve covers to match the truck paint. Not much, but here are some pictures:
Removed loom


Most of the tape gone and masking tape holding it together


This came off


Hope to work on the harness more this weekend as well as order the parts I mentioned just need to figure something out with the 3 different part numbers.

[jeebalow]

I started cleaning the engine today and noticed that there are 2 exhaust manifold bolts broken in the head on the driver side. Hopefully I can get those out without too much trouble. Picked up some black engine paint as well. Also got most of the harness reworked today. I spent about 8 hours on it while watching TV. I used the information on lt1swap.com to rework it. There is TONS of info there. For some reason I couldn't figure out what to do with the AC Compressor wires, but I need to removed them and just use the wires currently on the truck for that, funny how I just remembered and could figure it out all afternoon.

Do any of you know which wires on the 05+ Fan relay/fuse block are the fan 1 and fan 2 signals from the PCM? I have the fuse block, just need to know which are the PCM signal in for each fan.

On to pics:
Taking the Blue covers off


Here are a couples shots of removing the pins




All the wires removed from the blue connector


Added a pin for Fan 1, just used one of the whites from the trans wiring since I have an NV3500


Now the red


All wires from red


All wires from both


Food break




All the wires I removed. This is all the EGR, EVAP, rear O2, and trans stuff I don't need


Todays result just need to remove the A/C compressor wires and double check the routing before covering it up.

[Chriscon7]

Holy crap....

I wouldn't know where to start or what to do. Props for figuring that crap out!

[ladyzm18]

This is great! Can't wait for updates


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[jeebalow]

Holy crap....

I wouldn't know where to start or what to do. Props for figuring that crap out!

Thanks! It's really not that bad once you familiarize yourself with the harness. I just uncovered everything and labeled every connector by looking on lt1swap.com. All the information is there!

This is great! Can't wait for updates
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Thank you, I can't want either lol!

[Monstar_est87]

Man that harness did look like a pain in the ass... But looks like ur doing gr8... Ill be tuned in to see the final product...