Used 1984 Buick Grand National Used 6.0 LQ4L Automatic Gasoline Coupe

Seller Description

Video of car driving https://youtu.be/cHHXH75xxG4
Hello! This is my car, I did all the work on it, and I can answer any questions. I am a semi-professional EFI tuner (my main job is developing manufacturing software). Please read everything below. I tried to document everything and take lots of pictures with labels. I set this car up to be a basic 9 psi, pump gas, low maintenance, fun hot rod, and it is just that.
This car is not emissions-compliant in California (or states that enforce the same standards on cars this old).
Body:
Real 84 Grand National - 99.9% rust free west coast car with all common G body problem areas photographedVery straight, very clean, beautiful 37 year old car, compliments everywhereClean title no known accidentsOdometer shows 169k milesOnly known rust spots are front corner of driver door - door jamb was repaired at some point. There is a small pit above passenger door that has not advanced in last 7 yearsSome light paint fading on roofLast owner spent $7000 painting car 6 months before I bought itAll original sheet metal, never removed from frameOriginal 84-85 15x7 aluminum wheels, 2 extra 15x8.5 replicas includedNew spoolfool bumper fillersNo T TopsOriginal 84-85 hydraulic brake booster with no problems unlike 86-87 electric brakes
Interior:
Full dynamat on floor and roofOriginal 84-only Lear Siegler double lumbar seats rebuilt with new padding - power driver seat, leg support extends, passenger seat is manualFactory console with 4th gen F body shifter with correct detents for 4L80ESale includes original Buick radio, extra mint grill, new set of weather stripping, other small GN partsElectric windows work, vent works, rear defrost worksNo heat or A/C (heat could be easily hooked up and A/C is not removed from car)Fuel gauge works, speedo does not work with 4l80E - Holley EFI has speedoBluetooth stereo, new recent 6x9 rear speakersE brake worksRemote driver mirror worksBlack carpet, black headliner, OE driver black door panel, some panels painted black
EFI:
Holley Terminator X Max EFI mounted in passenger footwellControls LS engine, 4L80e transmission, engine fans, trans coolerCan control boost and E85 if future owner wants to add
Engine:
6.0 LQ4 with "Gen IV" floating rods and .030" over OE-type pistonsOriginally purchased through LKQ, refreshed by Machine Tech in Oceanside, CA at time of conversionHolley 302-2 swap pan, engine side mounts, transmission crossmemberLS9 head gaskets, stock head boltsStock 317 heads with .660" lift dual valve springs, locks retainers, rocker trunnion upgradeElgin "Sloppy Stage 2" camshaft 228/230 @ .050, .585/.585 lift, 112 LSAIdles at 825 RPM in gear - 12 inches manifold vacuum (not required for hydraulic brakes)Stock LQ4 truck intake, fuel rail, regulator, throttle bodyReal siemens deka 80 lb injectors
Turbo:
Hooker turbo LS driver manifold, fabricated crossover pipe, passenger log manifoldOn3 7875 turbo-4 AN oil feed with restrictor-10 AN oil drain to timing coverTurbosmart 50mm wastegateNo BOV3" aluminum piping into intercooler31x12x4 front mount intercooler3.5" pipe out of intercooler3" downpipe into 3.5" single exhaust with catalytic convert and bullet muffler
Cooling:
G Body 305 "tow package" El Camino radiator from Auto ZoneFord Windstar electric fans - about twice the CFM of LS1 4th gen f body fansCan be driven in 100+ degree stop-and-go summer cruise nights without overheating
Engine accessories:
Engine oil cooler mounted in frontFactory silverado crank pulley with ARP boltSilverado power steering pump with coolersmall case "car" LS alternator for hood clearancesilverado water pumpStock truck coilsNGK TR6 spark plugsEbay "nascar" spark plug wires with great heat shielding
Transmission:
GM Goodwrench 4L80E that was new in crate 7 years agoTransgo shift kitCircle D triple disk billet converter they built to provided specsTransmission has been 100% awesomeStock 6.0 flexplateStock 2500 Silverado 4L80E locking dipstick
Fuel system:
OE grand national fuel tank and hanger with Walbro 525lph "Hellcat" fuel pump10 GA wire and 40A relay to rear, run by Holley EFI3/8 feed and 5/16 return Dorman OE-style vinyl fuel linesUses fuel filter from ~2013 660hp GT500 (3/8 quick disconnect on both sides available at any Auto Zone)
Rear-end:
Original 8.5" 3.42 posi 10 bolt "Grand National rear end"Passenger axle replaced with aftermarket after wheel stud broke
Chassis:
Wilwood 12" 4 piston front disc brakes - much better, safer, and lighter than factory discs on original spindlesFactory rear drumsRear upper and lower tubular control arms with RUBBER bushings for smooth street drivingFront upper and lower factory control arms rebuilt with new rubberOE-style shocks all the way aroundFactory G Body Monte Carlo SS 305 "handling package" coil springs that sit very nice with the weight of the LS/4L80ECar rides very comfortably "like a Buick"New front sway bar bushingsCar drives nice and straight but could use front tie rods eventually (I believe original)Original steering box with no noise
Common Questions:
Question 1: Do you have the V6?
No. The 4L80e is run by Holley EFI, and COULD be used with the v6 with an adapter. Holley EFI can also run the v6 if someone wants to convert it back. No permanent changes were done. The LS is installed using OE 5.0 regal mounts.
Question 2: Is it a real Grand National?
Yes. It is a real "hot air" Grand National, not a T Type, not a Regal, not a clone.
Question 3: How much power does it make?
I do not know. Never dynoed. Tuned by me on the street. Research sloppy mechanics "dont bs me" combo for similar 7875 turbo LS numbers.
Question 4: What does it run in the 1/4 mile?
I do not know. I have only used this car to drive my kids to cruise nights. I have not raced it. It does not have a driveshaft loop or some of the other items required to run NHRA. If you want to race it you will have to check with your local track what they would require.

The closest regularly operating 1/4 mile drag strip is 6 hours from me.
Question 5: How fast is it/how powerful is it?
It will fry the tires from 30mph until you lift. Fastest car I have owned/been in - you may think differently.
Question 6: What kind of gas does it use?
I use pump 91 octane. No methanol/water.
Question 7: How reliable is it?
I have been semi-daily driving it for 7+ years. It has been on a few 1000 mile trips to other states. The engine and transmission seem to be about as reliable as if they were still in a silverado.
History:
Purchased car in Chehalis, WA. Originally sold in CA. Owned back-and-forth by same family (traded between brother-in-laws) since new. Car was all original when I purchased.Original 3.8 wiped camshaft on way to California. Car included two more 3.8s - both had cracked blocks. Made the decision to swap to turbo LS combination for greater power and reliability on pump gas. Originally used LS 411 PCM and HpTuners, switched to Holley EFI TerminatorX when it became available.
.