LS in 97k1500 parts list!

[Ehall8702]

I have a complete running,driving 01 suburban that's rusty asf! Motor runs great and trans shifts perfectly.i have been maintaining this suburban for a customer for 10 years now and they took good care of it. I literally got it for nothing. Checked rpo codes as at first my only interest was rear end ( gt4 g80) bc I wanted disc brakes wasn't sure if I was going to fab 4 link mounting plate and use factory setup or just weld perches on and use leaf setup already in my 97. Well now my urges have turned into LS swap, rear 4 link with airbags and 6" rcx lift, and gear change. I put a rebuilt 98 4l60e in my 97 and it's been solid so I have a choice between either trans to use. I have a floor shift tcase in my 97 and want to keep that, push button auto in suburban. Not sure if tcase is interchangeable or not, haven't looked too hard at it. Didn't pay attention to if it's a drive by wire or throttle cable but think it's cable. Didn't look at ecm but assume it's a 0411.
I am a mechanic and fabricator so crossmemeber issues and things like that aren't an issue.
Ideally I'd like to just put the 5.3 right to my existing drivetrain, worse case 5.3 and trans it's hooked to would go in, but don't want an auto tcase.
What is involved in mating 5.3 and my 98 trans? I know they bolt up but do I need an adapter or can I use flexplate from one or other and torque converter from one or other and not need to buy other parts?
I know I will have to get a tune , that was planned either way, I will have a full harness for the suburban too,but am thinking I will be able to merge the two harnesses to make it all work pretty easily.
I've tried reading threads on what all is needed but not alot of them have a complete donor vehicle like I do so the list of parts to buy don't really apply to me.
Also have a rust free cab I'm prepping to drop on this frame since my old cab is pretty shot. My frame is solid so it'll get wire wheeled and POR painted while cab and bed is off. Luckily I have a two post hoist so it'll make things a bit easier. Complete can is getting bedlined with a charcoal grey with flecs in it , **** ton of sound deadening, black suede headliner, recovered seats from the burbon , custom door panels and a b pillar wall with 4 18"s. It's alot of work but gonna be worth it in the end. I have HUGE pile of parts already ( about $2500 so far) and am about to the point I can start building this truck! I'm just trying to figure out what I have missed.
I see guys are saying a fuel pump swap is needed but I don't think it is, 5.7 takes 56-62psi and the LS takes like 59-62psi ( can't remember off hand but checked all specs earlier today) and both have a return line,and LS has regulator right on rail. I have pump and tank from suburban I could make fit if I had to but don't think it'll be necassary. What else am I missing?

 

[stutaeng]

I don't think you have to swap fuel pumps. I found a specification on performancetruck.net and it covers most GM engines. I can post it this weekend.

I would say if the transmission on the doner regularly got service I would just swap that along with the engine. Keep yours as a spare.

For the rear axle I would try to find a TRUCK 99-02 axle to gain the discs. 3.42 or 3.73 I'm guessing is what you want?

I personally wouldn't try to convert the coil spring from the SUVs to the leaf spring on the trucks... unless I was across overseas...they literally made a lot of the 99-02 trucks. I'm sure you can find one locally.

I did a 4.3 NBS to a 5.3 thinking I could merge the wiring harness, and didn't work for me...just use the LM7 harness and weed out stuff you don't need.

 

[Ehall8702]

I don't think you have to swap fuel pumps. I found a specification on performancetruck.net and it covers most GM engines. I can post it this weekend.

I would say if the transmission on the doner regularly got service I would just swap that along with the engine. Keep yours as a spare.

For the rear axle I would try to find a TRUCK 99-02 axle to gain the discs. 3.42 or 3.73 I'm guessing is what you want?

I personally wouldn't try to convert the coil spring from the SUVs to the leaf spring on the trucks... unless I was across overseas...they literally made a lot of the 99-02 trucks. I'm sure you can find one locally.

I did a 4.3 NBS to a 5.3 thinking I could merge the wiring harness, and didn't work for me...just use the LM7 harness and weed out stuff you don't need.

Well my reasoning for the 4 link setup was bc if the 6" lift, I'd be building ladder bars regardless so it'd elinate the need for a ladder bar, wouldn't be to hard by looks of it. At bare minimum I'm going to add the rear from the donor and just strip 4 link mounts and weld spring perches on , that will let me set pinion angle properly for the lift anyways. The pick up truck axles to use them would be sum "redneck engineering" as the spring width ( more like frame width) requires washers and things to bring width in to use existing spring pads, rather do it right and take the opportunity to fix pinion angle AND clean and pain the axle anyways.
As for the harness , I appreciate the advise, I'll drop in the whole harness and save myself sum issues. Was under the impression I could do the pin mod to the 0411 ECU and then splice in the proper sensors and eliminate the ones I don't need with a tune. Def saved me sum headache.
I think you are right with fuel pump, numbers are good, just was worried about volume or something else I didn't catch.
I haven't looked at the tcase yet. I'm not sure if my tcase will mount to donor trans. If I remember correctly , some trans had 5 holes for tcase studs and some had 6 holes. I def do not want an auto tcase in my truck! Damn pump wearing thru the case issues I've already dealt with quite a few times in the past, not a hard fix but not something I wanna deal with. Plus I'm going to add a posi lock and like the lack of electrical issues of push button 4x4.
the axle thing I'm gaining disc brakes yes and the newer ones are a bit stronger, I'm already digging into gearing options, going to end up in 37s so I'm looking at 4:88s that may end going in when I do the lift.

 

[Ehall8702]

What are the thoughts on brake system? Can I use my current brake system and just hook new rear end up like old rear end? Would I need to remove the rears from the abs block since I'm sure the rear line would have a restriction so the old drums wouldn't lock up as hard?

Also just ordered 513s for the axles under donor as I'll be swapping them into this when I put the lift on.

 

[stutaeng]

The 99-02 1500 series trucks had rear disc and the 03-07 went back to drum. I'm pretty sure on those trucks they just swap a proportioning valve on the drum trucks to convert them to discs. I would imagine the GMT 400 would be similar.

I thought you were swapping axle to gain discs, but you are going with much larger tires. Have you considered swapping a 14 bolt axle instead? I don't think there's a huge difference on the GMT 400 10 bolt vs the GMT 800 10 bolt in strength...and I don't think they are all that strong when abusing them.

The 14 bolt 6 lug from the 2500 Light Duty trucks would be a direct swap, just you still have drums...but I think those drums may even be an improvement over the lighter rear discs of a 1500 truck.

Another option would be a 14 bolt 9.5" disc axle. There's a way to convert those from 8 to 6 lug using some off-the-shelf parts from a Chevy Express van...

or a 2KX truck axle. Those are essentially what just described above, but they came from the factory like that. I bought one if those axles and planning on swapping into my truck with the 10 bolt soon.

 

[Ehall8702]

The 99-02 1500 series trucks had rear disc and the 03-07 went back to drum. I'm pretty sure on those trucks they just swap a proportioning valve on the drum trucks to convert them to discs. I would imagine the GMT 400 would be similar.

I thought you were swapping axle to gain discs, but you are going with much larger tires. Have you considered swapping a 14 bolt axle instead? I don't think there's a huge difference on the GMT 400 10 bolt vs the GMT 800 10 bolt in strength...and I don't think they are all that strong when abusing them.

The 14 bolt 6 lug from the 2500 Light Duty trucks would be a direct swap, just you still have drums...but I think those drums may even be an improvement over the lighter rear discs of a 1500 truck.

Another option would be a 14 bolt 9.5" disc axle. There's a way to convert those from 8 to 6 lug using some off-the-shelf parts from a Chevy Express van...

or a 2KX truck axle. Those are essentially what just described above, but they came from the factory like that. I bought one if those axles and planning on swapping into my truck with the 10 bolt soon.

I'm only swapping the rear end bc I have it already ,like I said it's a gt4 g80, so has an Eaton in it, and I'll be putting 5:13s in soon. Plenty strong enuff for 37s or 35s since I don't wheel it, I just want it to look the part. And yeah I haven't paid alot of attention , but I don't think there is a porportioning valve outside of the abs block on the gmt400s. Idc about abs anyways so I'd happily bypass the abs block and remove it which would make room to mount the 0411 ecm anyways lol.

 

[Ehall8702]

And the abs block out if the way would make it easier for my mounting my battery banks under the hood so it wouldn't all be a loss...my main concern is the tcase now, really should roll under neath the Burban and see if it's same bolt pattern, sure it is but don't like surprises.

 

[Ehall8702]

Still digging and reading ...donor has jc5 rpo which is vacuum assisted 4 wheel disc so I'll be swapping at bare minimum the master and possibly the booster if it's bigger and fits the firewall if the 97. I can't remember if the donor has single or dual piston calipers on the rear tho. I'm looking to utilize every part I can off the Burban to upgrade the 97 I can before I scrap the Burban. Anyone have any thought on using the aluminum rear shaft vs the fiberglass coated steel one I have? Not sure on lengths but suburban wheelbase and extended cab 6'6" box is almost same size, but after a 6" lift the stock shaft is on the thinking of too short so an extra inch or so would be a good thing as long as not too long to bind when compressed. Anyone know of any other parts I should be thinking about taking before I scrap the donor?

 

[Ehall8702]

So I'm the kind of guy who lays in bed and works on trucks in my head, and I've been thinking the Burban has dual piston from brakes, well I want em! Figure I'm going disc ontop with mc from donor might as well take fronts also. Now how to do it. When lift goes in all the control arms come off, am going to see how the nbs arms line up with OBS mounts. Would be nice to just swap knuckles but the nbs and OBS r too different for it to be that easy. They haven't shipped my lift yet so maybe I get a nbs lift kit and slightly modify the bottom drop bracket to fit OBS frame mounts then I can run the nbs setup. Wonder if that'll change width up front tho. Axles r same ,not worries about bearings and stuff as it's all there. I'll be swapping in the new front diff from nbs when lift goes on so it'll all be apart . I know it's all overkill but in my eyes this will be my truck for the next 20+ years and I want to get all the big stuff out of the way all at once and want to do every upgrade I can while I have the parts and time.

 

[Ehall8702]

This has turned into a rant but maybe it'll help someone out! So nbs knuckles will go on OBS arms IF you get a 2 pft ream and ream upper and lower ball joint holes, that's my goal now. No sense doing a arms as I can't find measurements but I will check before I ream and when truck is on my hoist and parts are in hand. As for brakes I'm goin to remove abs block and go old school with brakes and run 1/4" line from nbs master to everything so I get max out of my brakes. This truck will be my daily driver but I only drive about 10 miles a day and I come home for lunch. It'll probably never see the highway for longer than an HR or two. I wanted to lean twords 4.88s but we have so many hills here even a stock truck with stock tires drops in and out of OD all the time, nd after spending the cash I'm spending I'd rather have to run 60-65mph to keep tach down vs struggling any and constantly shifting. I'm still looking for tires I want but will be getting 37s or 38s , a 12.50 tho I don't like wide tires bc the 20s I run are close to stock offset and I'll rub frame, I don't like my tires to stick out past wheel wells but think it will be enevitable and as mush as I hate wheel flares I'll probably end up with a set