I have a '66 Skylark GS with with the optional Q-jet 340 hp 401....It's rated at 340 hp, which is 15 hp more than the standard 325. It uses the Q-jet, a slightly different cam (pn 1368091 ...the 65-66 8bbl, and 65 425 cam), and the 8bbl spec distributor....I've only driven the car in my driveway, so I can't tell you the performance... I imagine a later 800 cfm Q-jet could bump up the hp a bit. The '66 Q-jet air cleaner looks the same externally as the std air cleaner, just the carb opening is bigger.The air cleaner from a '66 Riv GS which is the same, but chrome!....:grin: Using a Fram filter element, it really strangles my engine....to the extent that, I thought 'why is my car running like @&^%$*?!' If you want performance, don't run the standard air cleaner.... I run dual quads on my blue car....a pair of 500 cfm comp series AFB's.... I tried a '66 Q-jet and gained a noticeable top-end improvement, and lowered my et by 2 tenths!:TU:
George: I don't know your reasoning for wanting the stock apperance, but I do know that you will sacrifice performance using the stock aircleaner setup. Also I have two q jet manifolds using the early 70's q jets and haven't had a problem putting them on the manifold or with the linkage. Mike
I don't think a 340 HP 401 was ever made and I also don't think it came with a Qjet. To the best of my knowlege, only a 425 came from the factory in '66 with a Qjet. The 401 was only 325 HP. Also, the dual 4 distributor uses ported vacuum, and the Qjet dist. uses full manifold vacuum from the fitting on the front of the carb. The setup you have must have been added on to your car. Please correct me if I am wrong, I don't mean to criticize you.uzzled:
I'll need to dig up some of my 66 Buick literature, but I believe 340 hp quadrajet was an option on 66 skylark gs. Dan
This was an option.very few were made. there is documentation to prove this..for some reason i have it in my head that these cars came with a TH400 instead of the ST300 but i could be wrong on that..Bob
That just doesn't make sense. I can see a larger carb making more HP, but you'd think that if that's the case the '66 425 would have also made more HP with the Qjet on it as compared to the'64 and '65 425 which made the same HP with the single carter carb. What I'm saying is that if a Qjet 401 is 340 HP and a Qjet 425 is 340 HP that is screwy. Not only that, Buick could have just put the 425 in there if more HP was their goal. The literature I have says nothing about this option.o No:
A couple of things: GM's prohibition on over 400 CI at the time, A bodies 1966 was a transition year and they were trying to get rid of nailhead items, while not having to build any more than possible, some say that was why the factory installed dual quad option for Riv (MZ motor) was made available right at the end of the year. I don't know when the Quadrajet option was made available on the 66 Skylark Gran Sport, but I'll bet it was late in the year to get rid of the extra quadrajet manifolds. I am looking at a Feb 1966 Hot Rod magazine Buick Motor Division ad for the Skylark Gran Sport on pages 50-51. It shows both carbs and a little bit of each manifoldfrom the top: Under the AFB it says: "The standard engine. Bhp--325 @ 4400. Torque--445 lb.ft @ 2800" Under the QJet it says: "More Engine. Extra Cost. Bhp--340 @ 4600. Torque--445 lb. ft 445 @ 3200. Carburetion--Quadrajet 4BBL." Dan
it was all a numbers game...remember the 70 455 in a GS made 350 hp while the exact same engine in a riviera made 370 hp..stage 1 only added 10 hp to a standard 455....also since both the 401 and 425 used the same heads the 401 would have better volumetric efficiency than a 425 and might respond better to a Quadrajet..(just speculation ).a 401 should have a higher hp peak than a 425 also. Bob
That's interesting. I'll bet the DQ cam helps to boost the HP, along with the additional CFM of the larger carb. I didn't think the difference between cams was that much.:bglasses:
Options The GS 401 Q-Jet engine was option L-76 according to the option list I got from Sloan. There is a guy here in Cincy (musclecared) that has a nice one. Per 1966 Accesory and option codes: #L76 A-9 Engine-High Perf. V8 Note: 400 Cu. In. 4 Bbl. Quadrajet Carb. (Note: To be used with Auto. Trans. Only & N. A. on Air Cond. or Air Cond. Mod. Jobs) 446
From a Buick dealer bulletin dated March 11, 1966 (group # 64-17, Dealer letter # 66-128): "Carter dual 4-barrel carburetors are now available as a factory option A8 on Wildcats and Riviera Gran Sports. A Rodchester Quadrajet carburetor option A9 is available on the Skylark Gran Sports. These options are available only on automatic transmission equipped cars. To provide extra performance these options include a special distributor (initial timing 12* BTC) and a high speed camshaft (same as 1965-425 engine). Cheryl
Mike,the only reason i like that stock look is because i love the way that aircleaner looks when u lift the hood up. Thanks
Re: Options Ted, could you elaborate on the list from Sloan....or could I even get a copy from you? I do have a 'dealer price list with RPO codes' on it's way to me...is that what you have? Someone once mentioned a 'L-76' option....is that on your list? I'm collecting all the info I can on these GS's with the Q-jet option. As I posted earlier, I have one of these cars in my garage, slowly being restored.... Info I have so far: - '66 GS order form showing availability of A-9 ' Wildcat GS' engine option - Info sheet from '66 Buick Selling Manual - Service Info Bulletins - A few old road tests with optional engine - Production numbers were published in the Steve Dove book...a total of 136 cars, I think. - and of coarse the CAR, with protecto-plate:grin: If anyone else has info to add, I'd appreciate it!:beer
I'm surprised they didn't just put the dual quads on them instead. If they added 20 HP to the 425, you'd think they would add at least that to the 401.:Brow:
Walt, what you could do is ask Sloan for the Daily Car Report summary for the GS models. I have them for the Wildcats, and they are handy for this type of info. I have to look up something about the wildcat GS convertible now...:Brow:
I have a magazine add, framed, and hanging on my wall from 1966. It shows a q-jet on a 66 skylark/gs, and advertises 340 horsepower option. So , yes, it was an option. Frank
:Smarty: That option was included on a few road test cars as well: - Motor Trend, July 1966 - Modern Rod, March 1966 - Car Craft, May 1966 - Mentioned in 'Blueprinting Buicks for Action', Hot Rod, March 1966 About the restrictive air cleaner....Russ (from Yahoo Board), said he flipped the element upside down, (so the sealing lip is down), to improve airflow. Others have drilled holes into the base (GASP!) for the same effect. It is a sweet looking air cleaner, especially when it's chromed!:grin:
