LS Engine Swap Question to the Collective

[thepunisher]

I'm stuck, so I figure I'll ask the collective for your opinions as to what everyone thinks. I want to swap the engine in my truck to a modern Gen III or Gen IV motor. The engine must have a manual throttle body because I am going to be using a 200-4R transmission. The two reasons for the 200-4R is I don't have to shorten the drive shaft, and I want stock gauges. I don't want a digital speedometer, and I don't what to run a digital to analog converter to make a electronic transmission work. Besides this would be a unique combination and I like that. I have a target of the engine making 400HP.

Options I have seriously looked at so far;

LQ4 or LQ9 - Good choices, 6.0L, makes good stock HP, from what I can tell the LQ4 should be a manual throttle body, so are the early LQ9's. Motors are a little more expensive and have higher mileage on them. Found one about 200 miles away, 82k miles for $850 for the motor, reasonable prices for the accessories, and computer, little spendy on the engine harness.

LMG or LC9 - Great choice, flex fuel motor, displacement on demand, makes 315 to 320 HP stock, found a complete LMG motor (all accessories, computer, engine wiring harness, exhaust manifolds, 17k miles delivered to a local shop for $1280). Problem is I haven't found a way to convert this to a manual throttle body.

classic Gen III vortec 5300 (not certain in the OPT code) manual throttle body, plenty or motors around which makes them cheap, good choices for after market parts.

[ShredSled]

Are you saying your target HP of 400 is crank, or at the wheels?

I'm gonna go ahead and say you want the 6.0 over the 5.3.
Potential is much higher than the 5.3's with their bigger bore, the power curve is going to be flatter with modifications as well. The 317 heads on the LQ4 and LQ9's are also the same as the heads on the LS6 243's which flow great, they are just larger chamber volume on the trucks. LQ9's have always had better rods and higher c/r, but the '05 and later LQ4's got the stronger rods as well, but retain the lower c/r dished pistons...

If you do for some reason choose to go for a 5.3, look for the lighter and more powerful all aluminum "H.O." version (can't remember the factory code, maybe L33?), although they are probably going to be a bit pricier...

As far as the flex fuel options, that's up to you. Not a big deal to me, DoD neither desireable to me, so can't really comment on those... I know most people who modify them in the newer trucks have that tuned out actually.

I like the cable driven throttle bodies better too, but drive by wire may possibly be tuned out, but this I cannot say for sure, hopefully someone else will chime in about it.


I've currently got an '05 LQ9 that I'm mildly building as my budget allows, with some L92 heads/intake and cam and other supporting parts. It will be swapped into my DD '02 Sierra in place of my cam'ed LM7 5.3 (which may actually find it's way into a '67 step-side)

[thepunisher]

Originally Posted by ShredSled

Are you saying your target HP of 400 is crank, or at the wheels?

I'm looking for 400 HP at the crank.

ShredSled - Is the '05 motor you have a drive by wire or mechanical?

[eagleuh1]

Even the DBW can be converted by switching to cable throttlebody and manifold, and using a PCM for a cable drive vehicle, or reprogram the pcm for such. You'll also have to add TPS and IAT sensors to the harness and setup if you have the DBW harness. I say go for the 5.3 if its going to be your daily driver, cost and milage wise its better. If going for higher power and not daily driver, go for the 6.0. I like my 5.3 and 4l60e, plenty of power and good milage too. Good luck. Jim.

[nomrlz]

Originally Posted by ShredSled

If you do for some reason choose to go for a 5.3, look for the lighter and more powerful all aluminum "H.O." version (can't remember the factory code, maybe L33?), although they are probably going to be a bit pricier...

and those have the 799 heads which are the same as the Z06 and even have the yellow springs just not the light valves.

i have an 04 5.3L for the boys truck and had the chance to trade it in on an L33 but didn't since he's only 11 and this will be his first vehicle and don't need the power

[ShredSled]

yep, in my case, all depends on which TB and intake (has bracketry for cable) I bolt onto the motor. I'm using a harness/pcm for the cable trucks too.

I know in some cases some people have actually seen improved mileage with a 6.0 swap over the 5.3, but most of those are typically heavy 4X4 lifted trucks so probably won't apply to your situation.
The 5.3 motors also go for dirt cheap since they are so common.

[thepunisher]

Are the intakes universal to the LQ4 and LQ9 motors? If I buy a motor that is DBW can I just buy a cabled throttle body and do the swap?

What about the L33, that motor looks like it was on the 2005 to 2007 G4 GTO's, is that DBW?

[Ackattack]

Originally Posted by thepunisher

Are the intakes universal to the LQ4 and LQ9 motors? If I buy a motor that is DBW can I just buy a cabled throttle body and do the swap?

What about the L33, that motor looks like it was on the 2005 to 2007 G4 GTO's, is that DBW?

04 GTOs had 5.7L LS1s
05 and 06 GTOs had 6.0L LS2s

[usmcchevy]

Originally Posted by thepunisher

Are the intakes universal to the LQ4 and LQ9 motors? If I buy a motor that is DBW can I just buy a cabled throttle body and do the swap?

What about the L33, that motor looks like it was on the 2005 to 2007 G4 GTO's, is that DBW?

For the cable intake and TB get one off a 99-02 4.8-6.0, they all use the same intake. Or if you want the car intake with cable operation get on from a 98-02 F-body (firebird/Camaro) maybe 97-02 vette also, but something tells me they were DBW already. Everything went to DBW in 03......or was it 05, I'm getting old

The L33 came in trucks as the H.O. option. It was a all alum 5.3 with slightly higher compression.

[thepunisher]

usmcchevy - to clarify are all cable intakes compatible with all ls style motors? Meaning an cable intake from an F-body would fit on any new LS motor (from a truck or a car)? If so that makes this makes finding the right motor a lot easier.

[usmcchevy]

Originally Posted by thepunisher

usmcchevy - to clarify are all cable intakes compatible with all ls style motors? Meaning an cable intake from an F-body would fit on any new LS motor (from a truck or a car)? If so that makes this makes finding the right motor a lot easier.

Yes.....until you get to the 6.2/LS3/L99/L92 I'm not sure.
One thing to remember though is if you have truck accessories its much easier to stick with the truck intake because if you try a car intake with truck accessories there is some modifications to get the intake to clear the belt.
Not to direct you away from this site but for some reasearch check out www.performancetrucks.net and LS1tech.net

[thepunisher]

So it sounds like the correct combination for me would be a LQ4/LQ9 with the mechanical truck throttle body, upgraded cam, heads, and headers. The more stock I leave the motor the more comfortable I'll feel. This does needs to be a streetable combination that gets decent gas milleage. I garage the truck when the snow hits the ground but otherwise I drive it quite a bit.

Does the LQ4 or LQ9 require a gas return line? I'm actively in the process of moving the tank to under the bed and would prefer to do the return line now if it's required.

[Shon]

Originally Posted by usmcchevy

Yes.....until you get to the 6.2/LS3/L99/L92 I'm not sure.
One thing to remember though is if you have truck accessories its much easier to stick with the truck intake because if you try a car intake with truck accessories there is some modifications to get the intake to clear the belt.
Not to direct you away from this site but for some reasearch check out www.performancetrucks.net and LS1tech.net

VERY TRUE. changing to the 'car' intake is alot more work than is needed. the truck intake is good up to 5800 RPM, and on stock parts this makes more torq, add in a cam that needs to go up into the 6k+ range then you might be better off with a 'car' intake but now that FAST has the 102mm truck intake I would just go that route.

It all depends on what your plans are for the truck, you can make it sound nasty and run pretty good with the truck stuff. mine for example is hauling butt with very little done, went 8.9 @ 80 on motor and 7.8 @ 88 on a 100 shot.

[Ackattack]

One thing about an iron 5.3L, it can be bored out to 5.7L easily and the can handle lots of boost (if thats you want to go)

6.0L or 5.3L, either way 400 HP at the crank is pretty easy with a cam swap and a few other minor mods.

One advantage of the 6.0L, is you can run the newer heads (L98heads????) that flow better than even the LS6 heads. You have to run a bore larger than 4 inches so they're a no go for the 5.3 and 5.7L engines.

All of the F-body (camaro / trans am) LS1s are cable operated as well.

[nomrlz]

Originally Posted by Ackattack

One thing about an iron 5.3L, it can be bored out to 5.7L easily and the can handle lots of boost (if thats you want to go)

alot of people do that and just use 5.7 LS1 pistons so it is very cheap as well

[thepunisher]

Originally Posted by nomrlz

alot of people do that and just use 5.7 LS1 pistons so it is very cheap as well

To start I would really rather avoid a trip to the machine shop. I'd prefer to keep this to bolt on components (intake/cam/heads/reprogramming the PCM).

[nomrlz]

Originally Posted by thepunisher

To start I would really rather avoid a trip to the machine shop. I'd prefer to keep this to bolt on components (intake/cam/heads/reprogramming the PCM).

just lettin ya know a rebuild is cheap when needed.

[Shon]

just get a DBW 6.0 and get a 224 int duration cam and headers and you will be close to your goals. for more umph lets put some Advanced Induction CNC'd heads on there.

The LQ4 is going to have lower compresson than the LQ9, and LQ4s might be cheaper since the 9s are the 'wanted' ones, but a simple head swap or milling will take care of the compression. I like the LQ4 I have b/c I can run 87 in it. Just keep in mind when doing a cam swap and milling heads to keep an eye on the Piston to Valve clearance, you will have to mill alot for this to be an issue on the LQ4 since they have dished pistons but something to think about.

I am using the 4l80 and stock gauges with the cable X box mounted on the fender.

My position on the L92 stuff is that it flows alot, and appears to make OK power but in the end you need ALOT of air flow to support them, meaning a big cam and high RPMS, and dont forget the offset rockers you need and depending on intake route you will need a specific intake for the L92s. I rather get the 317s, 241s, or 243s worked and head out.

If you go with LMG style motor make sure to get the TAC module or swap it to the cable style. and for the flex fuel side of that motor to really work, ie use E85 you need the oxygen "sensor" that goes in the tank so it knows what stoich AFR to shoot for rather than the standard 14.68xxx

[ShredSled]

yeah, I was going to mention that you don't want a car intake, but you guys got to it first. You don't want to have to deal with uneeded extra costs of changing out the accessory drives too.

And the c/r on the iron 5.3's is the same as the LQ4. They all love boost IMO, mildy anyway, the differences in c/r aren't that big to matter unless you're trying to make huge numbers.
I personally wouldn't bother with a bored over 5.3 either.


and I've actually got a spare truck intake and cable throttle body. So just let me know if you happen to need one after you find a motor you want if it's DBW... I'd let it go cheap.

[Sicmaro]

i used my dbw intake and converted to cable (04 tahoe 5.3)

[Shon]

Do the DBW truck intakes have a 4 bolt mounted TB?

[6D8_C10]

Originally Posted by thepunisher

I'm stuck, so I figure I'll ask the collective for your opinions as to what everyone thinks. I want to swap the engine in my truck to a modern Gen III or Gen IV motor. The engine must have a manual throttle body because I am going to be using a 200-4R transmission. The two reasons for the 200-4R is I don't have to shorten the drive shaft, and I want stock gauges. I don't want a digital speedometer, and I don't what to run a digital to analog converter to make a electronic transmission work. Besides this would be a unique combination and I like that. I have a target of the engine making 400HP.

Hey, I ended up getting a LMQ out of a 99 Silverado that was running.
It is the 5.3L. But like you I didn't not want to try and convert everything to digital. I also am doing something that everyone thinks is going backwards. I am doing the edelbrock carb conversion. I bought the engine for $600 and the conversion for $600. So I am only in at $1200 because I all ready have everything else.

I am also using a rebuilt 200-4r trans because of the same reasons.
Remember the "L" engines have a flexplate that is dipped in the center so a older trans (th350, th400, 200-4r) torque conver center nose will not reach. So you have to get an adapter so that it can reach.

[thepunisher]

6D8_C10 - Where did you get the adapter? Don't you have to use a different flex plate in addition to the adapter?

[Shon]

Originally Posted by thepunisher

6D8_C10 - Where did you get the adapter? Don't you have to use a different flex plate in addition to the adapter?

I got them for $35 shipped

And if you guys want quotes on the carb swap intake let me know. I am here for you guys!

[djw32]

Originally Posted by Shon

I got them for $35 shipped

And if you guys want quotes on the carb swap intake let me know. I am here for you guys!

Will this adapter work with the 700R4?

Where did you get your adapter for $35?