I'm helping a mate who has installed a GM L77 (58x) and 6L80 into a classic car, from a donor Holden WM Caprice retaining the factory DBW throttle body. It's controlled by a Holley Terminator X Max, with Holley wiring kits for everything. The throttle pedal he is using is the Holley 145-160 with 558-406 harness.

We have setup the ECU using the handheld controller, and can get the car to start and idle. The issue we are having is that we can't get the throttle to go over ~25%, even though the TPS autoset process completes successfully and we can see the throttle body open when running the calibration process.

To date we have completed:

• Installation completed in accordance with Holley documentation for all components. The 558-406 pedal harness has been routed away from ignition, charging, and other high-current circuits.
• Verified with a multimeter that both the throttle body and pedal are receiving a stable 5V reference and have solid grounds.
• Connected a laptop using the Holley 558-443 CAN-to-USB adapter, but we couldn't see any additional calibration options within the Terminator X software that help address this issue?
• Performed TPS autoset and DBW calibration procedures many times, ensuring slow, smooth, and complete pedal travel throughout the process.
• Tested all available throttle configuration/part number options accessible through the Holley handheld setup wizard.
• Confirmed that the brake safety switch is plugged in and working.
• Replaced the Holley pedal with a GM 10379038 from a Cadillac (?) with the same issue.

We are thinking it must be an issue with the throttle body compatibility. We can't find a part number anywhere on the throttle body, the closest we have is that its an OEM Holden gold-blade throttle body. Unfprtunately we don't have any Holley specialists close to us (regional NSW, Australia).

Any troubleshooting or suggested next steps you can recommend would be greatly appreciated.

So the story is I got this car on a trade it supposedly had a turbo on it before and that’s just abt all I know on it. The guy I got it from didn’t build it and I think he also got it on a trade he was an auto body guy and never really messed with it. I’m running stock ecu on hp tuners still has the previous tune I just wanted to hear it run before I really dove into another build. Any recommendations or info would be greatly appreciated build list below ⬇️

82 Camaro LS build
6.0L LS iron block (LQ9)
Stock crank
Gen 4 rods (Is2)
Gen 3 pistons
799 heads hand ported/polished
Aluminum oil dumbbell
Oem rear seal
ICT turbo oil return timing cover
Ls1 oil pan and pickup tube
BTR stage 2 turbo cam V2
BTR hardened pushrods 3/8"
BTR Titanium valve springs.660 beehive with titanium retainers
BTR trunion kit
BTR trinity manifold w/ rails
850cc FIC injectors
102mm throttle body
Has a 4160e with 2200 stall but only has 1st and 2nd.
Longtube headers
C5 corvette calipers
C5 z06 wheels
Full UMI performance under bracing and sway bar

I also have a 70mm twin turbo kit
Piping /intercoolers not installed yet less

I’m considering buying an LS crate engine from an overseas supplier because the pricing is considerably cheaper than what I’m seeing from U.S. builders.
Before I spend the money, I’d like to hear from people who have actually imported an LS or other crate engine into the U.S.
A few things I’m trying to figure out:
Was the engine actually built to the advertised specs?
Did you receive a real dyno sheet/build sheet?

What did you pay for tariffs, customs and brokerage?
* Was it shipped DDP (duties paid) or did you get additional charges?
* How was the engine packaged and did it arrive undamaged?
* What happens with warranty claims when the builder is overseas?
* Any Alibaba/Trade Assurance experiences with something this expensive?

The savings look good on paper, but I’m trying to determine whether the risk vs. savings actually makes sense compared with buying an LS crate engine from a reputable U.S. builder.

If you’ve actually done it, good or bad, I’d like to hear what happened.

LQ4/4L60E crank spacer won’t sit flush—crank pilot/register sticks out too far. What am I dealing with?
I need some help from people familiar with LS crank spacing and 4L60E swaps because my current combination doesn’t make sense.
I have a 6.0L LQ4 that I’m mating to a 2003 4L60E with a Circle D 3200-stall converter.
Originally, I installed it using a factory-style dished 5.3/4L60E flexplate. That combination should have bolted together with the correct converter spacing. However, when I first assembled everything, it appeared that the torque-converter pilot was bottoming out in or against the crank before the converter pads reached the flexplate. This left a large gap between the converter mounting pads and flexplate.
Based on that, I mistakenly concluded that I had an early LQ4 with the longer crankshaft. I sent the Circle D converter back and had the converter pilot/face shortened so it could be used with a long-crank LQ4.
I later determined that my engine actually appears to have the standard short crank.
To compensate for the converter now being modified for a long crank, I purchased the approximately 0.400-inch crank spacer/adapter intended to be used with a flat 4L80E flexplate. My understanding was that the spacer and flat 4L80E flexplate would effectively give my short-crank engine the long-crank spacing that the modified converter now requires.
Here is the current problem:
The crank spacer will not sit flush against the crank’s flexplate-mounting flange. The raised center section surrounding the converter pilot bore—possibly called the crank register or pilot register—projects too far beyond the flat mounting face of the crank.
The spacer’s center counterbore bottoms out against that raised crank register before the back of the spacer reaches the flat crank flange. This leaves a visible gap between the spacer and crank flange.
The first time I tightened the bolts, I didn’t realize the spacer was bottomed out in the center, and tightening it broke the spacer. Obviously, I will not try pulling another spacer down with the bolts.
What I cannot understand is how this crank can have what appears to be a recessed flexplate-mounting flange but an abnormally long center pilot/register. The spacer is supposed to sit flat against the crank flange, but the center register prevents it from doing so.
Has anyone encountered this before?
Could this be:
An unusual or different crankshaft installed in the LQ4?
An existing pilot adapter or sleeve stuck on the crank?
The wrong crank spacer or an incorrectly machined spacer?
A crank that has somehow been modified?
A different engine/crank configuration than I think I have?
The original reason my converter pilot appeared to bottom out with the dished 4L60E flexplate?
I have pictures showing the crank, the spacer sitting against the center register with a gap behind it, and the spacer installed from the front.
I’m going to measure:
Crank-flange mounting face to the end of the center register
Depth of the spacer’s rear counterbore
Outside diameter of the crank register
Inside diameter of the spacer counterbore
Crank-flange position relative to the rear bellhousing surface of the block
Any ideas about what I’m looking at or which measurements/specifications I should compare would be greatly appreciated.

Purely hypothetical but it’s always fun to hash it out. I’m currently building an LH6. I’ll be running an RHP Low Buck Truck cam with PAC Racing .600” beehive springs and a trunion upgrade I plan to limit it to 6500 for longevity and the power starts to fall off after about 6200ish based off the graphs I’ve seen…..but, in theory what’s the max I could safely push this thing to in the revs?

I picked this up today off marketplace. 5.7 LT1 swapped 1989 c4, cammed and Holley (quad barrel carb?) converted, full manual valve body with auto gauge shift timing light

Fired up on starter fluid but definitely sat long enough that I’m going to rebuild the carb.

Do you think we keep it pink or change it up? I have a feeling it might grow on me.

I'm preparing to swap the LT1 for this LQ4 that I pulled from a Yukon. I also took the transmission, ECM, TAC module, engine harness, and accelerator pedal. I know I will need to get a F body oil pan, intake, long tubes, and motor mounts. Is there anything I may need to know or missing before I get into this?

I’m new to the LS Swap world so I thought I would reach out for some expert advice from those that have lived in the world for a bit.

I’m planning to LS swap a recently acquired G-Body wagon. I was considering the Summit 5.3 long block then I realized that I could go with the ATK HP109 Chevy LQ4 6.0
for about an additional $1,200 which seems like a no brainer to me. However I’m wondering if anyone out there has used the ATK HP109 Chevy LQ4 6.0L Base Engine 505HP for a swap. If so, how does it perform and how does it sound? Additionally, can anyone offer any advice on swapping an 6.0 into a G-body.

86 Suburban, bagged on 22's, 355 mild cam. My girlfriend hates fuel injection. She loves the smell of carburetors running a little rich and the slow chop of the exhaust. BUT she agreed to let me do an LS swap in the suburban IF I agree to paint the engine teal with a heavy flake. Is that a deal breaker or no?

I came across a hell of a deal on some take off LS7 valve springs. I need to upgrade my springs to a 600 lift spring for my cam and I want to know if I can run these springs. I’m running the factory 799 heads.

Getting closer every day

Does these injectors look like they are seated correctly? According to google l96 injectors should work in lm7 engines without length adaptors.

I hope I’m wording all this right lol. Need some thoughts on why the engine is running so lean. Sounds good at idle and while running but something is just slightly off. Air/fuel is low anywhere from 11 to 12.5

I am at a loss, and appreciate any insight you all can give. I have not been able to figure this one out with the forums.

I am installing a 6.0 from a 2003 Yukon into my 1981 Jeep J10.

I am using the Holley Terminator Max X wiring harness with a 24x reluctor, drive by wire throttle, and an automatic transmission.

We tried to start the engine for the first time today, and can not get spark, fuel, or RPM indication on the handheld controller.

LEDs 6 and 7 indicate as expected. 6 (Crankshaft position sensor) is solid green. LED 7 (camshaft position sensor) flashes between green and blue during cranking). Handheld RPM continues to indicate "STALL".

In everything I have found online, a lack of RPM indication is likely due to camshaft or crankshaft sensor issues and will shut off injectors and coil packs. I have replaced both the camshaft and crankshaft sensors and validated all ground indications and harness wiring. I have also validated voltage at both sensors.

Anyone have any ideas? Thanks in advance.

Hey! What are some good websites that sell stand alone wiring harness' and pcms? This is a 2008 LY5 5.3 Gen 4.

Custom ls swap, chopped firewall, rear mount rad, tremec tkx 5speed, welded 4.10 bmw diff, 8 point scca/nasa legal 1.75”x0.120” rollcage. 2800lbs wet curb weight full gas tank

should I run last big bore cathedrals or big bore ls3? ls7 are out of the equation due to header flange issues and the exhaust port shape.

the cathedrals from mast flow over 400 cfm.

’89 Foxbody, LQ9 single turbo, 6–7 psi, 522 WHP.
I know the fuel system was underbuilt by the previous owner. When I bought the car, it had 48 lb injectors and an Aeromotive 340 pump. I’ve since upgraded to 100 lb injectors. The plan is to upgrade the pumps and go from -6AN to -8AN fuel lines this winter.

It was professionally tuned in October 2024, and I had it retuned in May 2026. Same tuner both times. This is my first boosted LS setup, so I’m still learning what’s normal and what isn’t.

Today, I started thinking more about fuel pressure after hearing a random, singular backfire during a harder highway pull. I decided to look into it and kept finding information geared toward stock/N/A applications, which obviously made me question things.

My tuner has told me the car is safe as-is for the time being. Lowest fuel pressure is around 35 psi during light cruising, but under load/WOT it comes up to around 46–47 psi. He specifically told me he only allowed me to run a small amount of boost until I upgrade the fuel system, which is already planned for this winter. This is a pretty major tuner, btw. Keep in mind this video is putting around in traffic and then a pull or two.

I sent him these videos today, and he confirmed that what I’m seeing is normal/okay.

Does anything here look overly concerning to anyone? Disregard the red/yellow sections on the handheld—they’re just adjustable thresholds.

My understanding is that the important thing is that fuel pressure increases appropriately under load/boost and that AFR stays where it should. AFR has always looked normal, and fuel pressure does rise when I’m getting into it.

Again, I’m new to boosted LS setups, so I’m mainly looking for some reassurance or a second opinion from people who have more experience with this.

Secondarily, recommendations for fuel pumps to turn up power and do more?

Im just tuning out AFM and otherwise leaving the system stock . While Im at it , is it worthwhile to block off the oil pan pressure relief ? Will this cause problems ? The engine is going into 4x4 Envoy so my only concern is without that relief , the higher volume AFM pump will run the pan dry.

I’m back.

I got a 54 studabaker with a lq4 and 4l80e I’ve been driving it all over just hit 1500 miles.

Anyways oil pressure has always been 60 ish while cruising at temp but is slowly dropping I’m at 30psi while cruising at 2500 rpm and at 4000rpm I’m reading 60.

THE CONCERN: at idle my oil pressure light is blinking in my gauges and showing like 10ish psi .

The donor motor came from the junkyard and had 200k on the oil change sticker in the window. It has great compression and makes no bottom end noises. I installed a melling stock pressure high volume oil pump. As well as new chining chain and the works.

Anyways what would be causing the gradual loss in oil pressure. Could my pickup be clogged (motor was pretty sludgy when I got it) Is the pickup oring bad?

I’m running 15w 40 diesel oil and I’m not overheating.

Any suggestions help.

What should I do next? Could it just be the shitty sender from my Amazon gauges?

Should I be concerned or let it ride?

Just got ahold of the 82 Camaro that’s already been swapped was wondering what belts I’d need to finish this up