Any interest in discussion about the above from late 60 ‘S to early 70 models
I love the GM “A” bodies and have owned or restored many of them, but don’t forget about the Lemans/Tempest/GTO’s! I currently own a 66 El Camino.
That’s one rare & beautiful vehicle ! It just seems the newer cars& trucks just don’t appeal to me anymore. I’ve got a 68 Cutlass “S” convertible which I bought new and sat in my garage for 20 years until I restored the body and interior over the past 5 years. The motor hasn’t been touched but runs like a top after 112,000 original miles. The carb probably needs rebuilding as the pedal has to be pumped a lot before it’s warmed up.
You might want to check that the choke is working properly. Also the Rochester carbs have a tendency to leak down when they sit for awhile, thus the nick name quadrabomb!
Thanks for the advise but I checked and it seems more than the choke,so
In the Spring I think I’ll rebuild the carb or would I be better off replacing it with something other than the Rochester ?
@fredwright0212 - While Quadrajets can be complicated to rebuild (there is a lot of linkages that need to be put back in place correctly), when running right they are fantastic carbs. It would likely be easier to rebuild what you have than to start from scratch tuning in something new.
I agree with Kyle on this. The Q-Jet is a great carb when it’s in tune. The small primaries offer great mileage and throttle response while the huge secondaries provide lots of air flow at higher rpms. You can try rebuilding it yourself, but some times the throttle plate shaft bores are worn requiring them to be machined out and bushed. Also, if you are using the stock intake, you would have to use another spread bore carb or use an adapter plate if you want to change carbs. Otherwise you would need to replace your intake. I personally don’t like any of the other spread bore carbs out there. Best of luck!
Late 60s and early 70s have always been my favorites. My '72 Chevelle SS is a numbers matching, low mileage beauty with a 350 mated to a TH-350 trans, power steering, front disc brakes and factory A/C. If I could afford them I would also own a '69 SS 396, '70 SS 454 and a few 442s.
My friend Brenda has a really nice blue 1970 442 with the 455. It wins a lot of shows and is popular at the cruise-ins. Took a pretty cool looking picture of it driving on I-95 a couple of months ago.
Both are beauties,Robert— there are dozens of old cars I’d love to have !My first car was a 1955
Chevy Belair convertible which I sold for $100.00 in 1966. Oh how I’ve kicked myself since then !That’s one reason when I bought the 68
Cutlass new, I vowed I’d never sell it
What do you think about buying a “new” Rochester carb from a reputable after market dealer or would that have the same problems you mentioned previously?
I would try rebuilding yours first as this would save a lot of $ and it is always nice to keep the original parts if you can. You said that your car only has 112k on it so there is a good chance that the throttle shafts are ok. I would, however replace the secondary needles and seats as this is usually the cause of the leak downs. The needles and seats are not usually part of the rebuild kit and you need to match the ones you have as there are different sizes for different applications. If you do decide to replace the carb Jet Performance makes quality replacements. I would go with one of their 750 Stage 1 Street Performance models if you motor is still in stock trim. These come with the fuel inlet in the front or on the side so make sure you get the one that matches yours. You may also want to check your fuel pump as a bad pump can also cause the problems you described. One more thing, I would add a second fuel filter in front of the fuel pump, it will extend its life significantly.
Definitely do the rebuild. There is nothing more reliable than a well tuned and adjusted Rochester. Alot are scared off by comments from individuals not doing their homework on rebuilding. There are plenty of books and internet info on properly rebuilding. https://www.amazon.com/Rebuild-Modify-Rochester-Quadrajet-Carburetors/dp/1932494189 Some here come to mind. I am 62 and have owned Oldsmobiles since I was 16 plus my father working for an Olds dealer, we have rebuilt many quadrajets. Once these units are set up they give many trouble free miles and good economy with the small primaries as stated by others. I have since purchased a 1967 442 that came with an Edelbrock (AFB) and Performer intake. I have rebuilt it out of simplicity but long for a 4MV. These AFB’s are great in their own right, having several in use on 2 Jeeps that my son and I own, and have to say the adjust-ability and simplicity to make changes without disassembly is great. Keeping your car original is always a better place to start than dealing with linkage and fuel line changes and so forth. Properly rebuilt you will be rewarded with long term reliability.
Thanks or the advice, I’ll give it a shot in the Spring when the weather gets better