By on March 24, 2012

After Joey and I sat down and tallied up all of the costs of our proposed Monte Carlo G-Body project; crate motor, upgraded cooling system, differential, engine accessories, transmission not to mention bodywork, interior refurbishing, brakes, suspension and all the other fun expensive stuff, we decided to abandon the project. Instead, Joey’s getting a Grand National.

Murilee himself advised that a GN might be the most cost-effective way to big power. The project in mind is to have a cool street car that looks and sounds good while still going fast. Most Monte Carlos are oxidized junk around these parts. Grand Nationals, on the other hand, are well cared for, and the $10,000 asking price for even a somewhat tired one is much more appealing than paying a couple thousand for a regular G-Body and then having to perform tons of work to bring it up to decent condition. A GN, while more expensive at the outset, is much more cost-effective in the long run, since we’re starting with a well-cared-for and capable car from the outset.

Anyone with turbo Buick experience is welcome to chime in with comments, suggestions, things to avoid and look out for. Ideally, I’d like to know what would be a good compromise between power and everyday driveability. The GN should be able to cruise on weekends for a few hours, but stock power levels won’t be adequate. At the same time, going with something severe like standalone engine management is too extreme. Any turbo upgrades would ideally improve throttle response and do away with the old school turbochargers. Coming from an import background, my knowledge of Turbo Buicks is weak. A rough goal would to eclipse the power of a stock GNX. Any good upgrades to the brakes, suspension, cooling system and any other important areas are also welcome. Joey and I will be going to look at Grand Nationals (hopefully by the time you’re reading this) and we’ll keep the B&B updated on the project. In the mean time, your collective wisdom and guidance is called upon!

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24 Comments on “G-Body Project Car Hell Part 2: Grand National Time...”


  • avatar
    Educator(of teachers)Dan

    Eh. Rather have one of the more “plebian” G-body coupes so I didn’t have to stop light drag every kid in a riced out Civic just based on looks alone. But then I was raised on Hot Rod Magazine and wanting to modify cars.

  • avatar
    JohnE

    The Grand National is a far better starting point from a financial standpoint, for all the reasons stated in the article. I had 2 of them. The first one was never modified, then second one appeared bone stock but would run high 11s on race fuel. It’s an excellent car for going fast in a straight line.

    • 0 avatar
      redmondjp

      Fast in straight line yes, but stopping and cornering, no. And rattletraps inside, not that it matters.

      I say this as a big GM fan that attended two years of college in Buick City (Flint). Buick used to bring these cars (GNs, T-Types, etc) to our college campus every spring for the car show.

      • 0 avatar
        AMC_CJ

        I have a few G-bodies myself, and you’re completely full of shit. Maybe if we were talking about my plain 78′ V6 Sedan, but my 79′ Malibu coupe is a far different car. Factory 4spd, F-41 suspension. The car is in like-new condition, and I’ve never heard any rattles. It stops fine, and yes, it can take a corner fairly well. These cars have a very nice chassis and for myself, I can make the car do whatever I want. A GN would be along these lines too.

        Sure, my 2012 Mustang sitting in the garage next to it could out corner and brake it, but, not by as much as you think….

        But you know, you saw a few at car shows when you were in college, so rattle traps and all right?

  • avatar
    ktm

    All you need to know about modifying a GN can be found here: http://www.turbobuick.com/forums/

  • avatar
    RRocket

    Put a Precision 6262 turbo on the car and it will be a beast on the street and at the track….

  • avatar
    Moparman426W

    Anyone who half knows what they are doing could get more power out of the Monte SS for alot less cash. For one thing it already has the transmission you need, it would only need an upgrade. All of the accessories and brackets on the 305 will bolt right onto a 350 or any other small block. The factory V8 radiator is more than adequate for cooling a performance built small block, depending on how much power you are looking for.
    If you add much power to a GN you will also have to perform driveline upgrades, as the drivelines on these were not particularly stout either. And if I recall correctly, the brakes on GN’s are the same as on the other G bodies. Finally, you keep asking for advice on making power without so much of a hint on exactly how much power you are looking for, so no one really knows what to tell you.
    It’s best to go to the forums on a particular car you are interested in for advice, or Hot Rod, Car Craft, or similar performance oriented publications. Since online car websites like this one are free most guys that frequent them barely know how to change oil.

    • 0 avatar
      derfhwt

      Moparman I have to disagree with you. Assuming they want to keep this a street friendly machine, why use th350 over a 200r4? Also the turbo 3.8 can lay down more power in a street friendly package than a 350 or 383. The 3.8 will make equal or more power plus be able pull decent mpg’s if you can keep your foot out it. If they are going to swap at all, and i’d only recommend this if the 3.8 is pretty tired; would be to go to an iron 6.0 or 5.3 depending on goals and budget.

      • 0 avatar
        Moparman426W

        Umm, no dude. A 400 + horse small block chevy can easily be built for less than 3k. Parts for turbo cars are expensive, Many turbo units alone cost more than that. Plus with a GN if you want peace of mind you have to replace the factory timing cover/oil pump with one from T/A performance or poston, since buick 231′s and 350-455 engines are known for self destructing unexpectedly due to failure of the stock oil pump.
        The last year for the TH350 in the monte was 1984, after that they all had the 200. The GN also has the same spindly 7.5 inch rear just like the monte. It’s possible the super rare GNX may have had the 8.5.
        So this person mentions that he would have to upgrade the suspension, driveline and brakes on a Monte SS like a GN would be better, when they both have the same suspension, driveline and brakes.

      • 0 avatar
        Power6

        Ha old post but you are way off

        GNs and 442 G-bodies had the 10-bolt 8.5. Monte SS had the 7.5. All of them had the 200-4R but the GN had the best “BRF” code version. I think any 200-4R can be built strong now. Back in the day you had to have that GN specific version.

        It is a trade off. You need to build a motor for the Monte the HO 305 is junk but they are cheaper to buy and cheaper parts. The GN will be getting on in the years so needs a bunch of maintenance like that front cover and timing chain (stock plastic gear teeth!) and the motor better be in good shape if you want to bolt on some HP. But a good one would go easy 12s with just a few tweaks its been done for decades now!

  • avatar
    acuraandy

    Having owned a couple of G-Bodys over the years, the cruiser appeal is insane. A guy I know knows a guy who has a mid-80s Olds Cutlass ‘grandma special’ with 3.8l V6 and around 40k original miles.

    They ride nice, don’t handle completely horribly, endless powertrain options, collectability (now).

    If budget is an issue, find an old ‘barn find’ base Regal and put the GN turbo on the (likely) 3.8l.

    That said, I WILL OWN a GN before I die. I don’t care if it’s 20 years from now and 87 octane is $20/gal. :)

    • 0 avatar
      Dynasty

      Yeah, I knew a kid in HS who lived up the street from me with probably an 86 or 87 Grand Prix. I’d ride with him to school on occasion. In spite of all the shortcomings these cars had, I remember it was a very comfortable car. At least riding shotgun anyways.

    • 0 avatar
      Moparman426W

      The GN may have had the 8.5, It’s been a long time since I have been around one of these. But the 8.5 is no paragon of strength either, it won’t hold up to serious power.

      • 0 avatar
        Moparman426W

        The wikipedia lists the 7.5 for the regal T type turbo, which was basically the same car. Like I said earlier tho it doesn’t make much difference if you plan to make serious power either one would need swapped out.

  • avatar
    Crosley

    I agree that financially speaking, if you want an “ultimate” G body, you’re better off starting with a Grand National. The initial price is obviously a lot more but you can easily recover most of that when it’s time to sell.

    If you throw $10k into a generic G-Body, you’ll be lucky to recover 20 cents on the dollar. A Grand National is a turn key hot rod that has everything to go, with a 4 speed, AC, 8.5″ rear end, and 11 second quarter miled with only a few mods.

    I had an 81 Olds Cutlass with a 455 and Th-350. After all the time money, and resell value, I regret not just buying a GN.

    Still, I prefer the lines on the Cutlass and it was a unique ride. I probably only “lost” what the sales tax on a new car costs.

  • avatar
    Maintainer

    If all you’re looking for is future resale value, yeah the GN/T-Type is the way to go. If you’re looking to build a fun car that you actually like looking at I’d build your first choice. GNs are fun and easy but if you like Monte’s or Grand Prix or Malibus it’s never going to be the car you really wanted.
    Trust me on this. If you settle, you won’t have the car you actually wanted and at some point you’ll regret it.

  • avatar
    EdSTS2000

    For modification and upgrade potential, it appears that even the famed 3.8 V6 has been eclipsed by the GM LS V8. Look at the following:

    http://www.hotrod.com/techarticles/hrdp_1109_stock_gm_ls_engine_big_bang_theory/

    Take a junkyard pull 4.8L LS, do heads, intake, headers, and cam = 450HP at 7000RPM. Add boost from eBay sourced turbos, and 1200HP from a stock bottom end!

    • 0 avatar
      Dynasty

      I just read the Hot Rod article. Amazing. It would be interesting if they could repeat the same test with other V-8s, say from Mercedes, Lexus, etc and see how well they would hold up under the same conditions, and their power output.

      Just more proof of how good the General’s LS motors are.

      I have a sneaking suspicion this motor could probably be tuned and sized to be more fuel efficient (w/cylinder deactivation) than many I-4s, are far more drivable too.

    • 0 avatar
      Moparman426W

      A stock LS block is only good for around 600HP, actually. That is why the aftermarket sells cast iron blocks for them.

  • avatar
    MrGreenMan

    Try to avoid making it into a Chevy by replacing the V6 with some sort of SBC V8.

    You probably want at least a 1985 if you’re keeping any of the internals, because the 1985 had the SFI and a couple nicer things otherwise.

    The 1985s were hot-air cars, whereas the 1986 and 1987 had the intercooler. If you are comfortable modifying the front aid dam, go get an intercooler out of a Ford Diesel pick-up, mount it low, get a better turbo, and then prepare to get a new fuel pump and injectors to crank it up on power.

    The original 200R transmission will likely be a POS, but the manual swap will leave you without an overdrive in the most common instances. You can get a high-performance 200R that can handle 300-500 torque and still give you boulevard cruising and expressway performance. Who really wants a G car that buzzes like a Civic or an Audi?

    Also, until you replace the turbo: It’s a Buick, not a Chevy. Oil pressure is going to be wildly between 10 and 60 pounds while you drive and accelerate. So long as it doesn’t reach zero, you’re fine. Also, the older turbos were particularly susceptible to burning up on park, so you have to leave it running for a couple minutes if you park it from a turbo boost.

    And….you missed Poston, which used to have every single part imaginable, and was a casualty of the Carpocalypse.

    Edit: The Grand Nationals that weren’t the coveted 703 GNX also had a few issues in the connection between the Flint and Pontiac pieces — namely, they didn’t use all the body-to-frame connection points, and they didn’t all have good sway bars. You want to add those and add a support behind the passenger seat like an X cross-member to improve the structural stability and get rid of the crazy cracking above the door.

    • 0 avatar
      Bill Wade

      I just sold two GNs for $7k each in good condition. While they were fun cars their day has passed. The build quality was absolutely terrible and all the bracing in the world didn’t prevent all the cracks around the doors, side rear and back windows. Electrical system was trash and water leaked everywhere.

      They were just another one of the cars that were poster children for why GM got in trouble. Missing body bolts, emblems on crooked, power window switches misaligned, screws laying on the floor from who knows where from under the dash and a myriad of other problems stemming from an I don’t care attitude.

      Can you imagine one of them didn’t have limited slip from the factory? Nobody ever believed me until they looked at the RPO codes listed.

      • 0 avatar
        ponchoman49

        The only leaks I have ever heard of on any of these G-bodies were old dry rotted T-top seals or door seals. Never have found any screws laying on the floor unless buck tooth billy bob tried cobbling an aftermarket radio into the dash. Never saw a misaligned window switch so that is a new one and the body mountings varied with the car model. Base model Regals didn’t get as many frame to body mounts as the turbo cars as it was felt the faster cars needed more body rigidity. Few mid size cars in 1978 had full frames and rigid bodies so these were pretty good for there time period. The goal was a smooth quiet ride not race track ready muscle cars in 1978. The slight crack on the driver’s door resulted from cars that didn’t have all the body mounts and as stated is easily remedied with the rear seat brace and additional body mounts in the middle area of the frame to body. Few cars offer the sheer versatility, adaptability, engine combo choices, lightweight body, aftermarket parts availability and sheer fun factor that these G-bodies offer. Limited slip wasn’t std equipment on any of the performance cars of this time period so why is it unimaginable that all GN’s didn’t have it? It was offered for those that lived in wet or snowy climates that wanted better traction. I have owned, driven and modified hundred of these cars so know what there short falls and problems are. I also know BS when I heard it!

  • avatar
    Flipper35

    I would grab a well cared for ’87 T-Type. Sleeper looks and you can get the additional performance out of them the same as a GN. Head gaskets would be something to watch out for on these.

  • avatar
    GS650G

    Get a fox mustang and go with a 351 and be done with it.


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