Newbe to this Olds site. I have a 1972 Oldsmobile Cutlass Supreme, 350, 4 barrel. I've owned the car for 9 years now and have been slowly restoring and updating it over the years, making sure I can still drive it during the warm months. This year's project was doing some work on the top end. The car has it's original 350 in it. I have not done any internal engine work on it since I purchased it, however the engine runs too good and has too much power to be stock. My assumption is that it possibly has a mild street cam, based on the torque and lower manifold vacuum. The heads appear original, however I am unsure if they have had work done prior to my purchasing it. I am installing an Edelbrock Performer intake. On the Quadrajet on it, I had the mixture screws backed almost all the way out to get the engine running real good. I have come to the conclusion that I have no business putting the old quadrajet back on and letting it keep starving the engine. I want up the carb to a 650. I'm torn between going with a Holley Double Pumper or an Edelbrock Thunder Series AVS. The car is strictly for street use and some say that a double pumper is a little much for street use, but others say they're great. I'm looking for advise from anyone who's had either of these on their cars. Thanks!

 

For street use you should have your Quadrajet rebuilt IMO. It is a 750 CFM and when done right is one of the best, most versatile carbs for the street. You don't mention gears or torque converter assuming you have an automatic. With a stock stall speed I wouldn't do a double pumper.
With regard to the heads, there should be a large # on the front of the head on the passenger side. That will at least tell you if they are the original 1972 heads. I'd also post the #'s off your quadrajet to see if that is the '72 as well.

 

X2 on a well prepped QuadraJet. Several companies offer several stages of performance Q-Jet builds from fuel economy to race (JET & The Carb Shop are two that come to mind). They offer a stock of new and rebuilt carbs or send yours in for a rebuild. The Edelbrock AVS series of carbs are good as well. I've worked with them and they are simple and very tune-able and stable once dialed-in.

 

I tried to decode the numbers on my Quadrajet with no luck. The casting number on it is:

017054938
0525

I always believed the 0525 was the CFM rating of the carb.

It has a "remanufactured" sticker on it so I do not believe it is the original carb. The numbers on the reman sticker are

47010002
07147072

As for the heads, the numbers are currently unreadable due to engine grime. I'll have to clean them up so I can read the number.

 

So you've had this car for 9 years and you have no clue to whats in the engine? But your but dyno and vacuum gauge readings from a poorly tuned carb tells that it has a cam in it. Sorry if I don't agree.

Tell us more about your setup, distributor, exhaust, trans, rear gearing... Also what tuneup specs are you running. Dwell, timing (initial and total), rpm at idle, and vacuum readings at idle. Are you using vacuum advance, manifold or ported?

 

Hopefully this helps

http://www.superchevy.com/technical/...s/viewall.html

 

Assuming the zero prior to the one is due to the replacement carb I see a replacement carb for a 74 cadillac built the 52nd day of 1975.

That also assumes your nine is incorrect because it should be a 1, 2, 4, or 5.

here's where I pulled that info from:
http://www.cliffshighperformance.com...carb_ID_2.html

I'm in the middle of reading his book right now and deciding whether to rebuild a very nice 72 olds 350 carb or a grungy 76 olds 350 carb for my 455.

 

I can't make heads or tails of the stamped number - they usually started with "70" or "170."
If I leave off the "0," "1705" should be a 1976-1979 carb, but the "4" should represent the year, and 1974 isn't possible if it's a '76 to '79 carb.
I can't find a listing for the "9" in the next position either, though a "3" in the position after that should correspond to Olds.
The whole number, starting with "0170" is a little weird, so I would suspect it is a service replacement carb, and not one specifically made for any particular model.

"0525" is a date code for the 52nd day of the year ending in "5," so either 1975 or 1985.
I would bet on 1985, when model-specific replacements for 1970s carbs were being phased out and replaced by generic "close-to-correct" units.

All QuadraJets until the late seventies were considered to be 750CFM models, with a number of the later carbs being 850CFM.

For the engine you describe, you will be much better off with a QuadraJet than either of those others you mentioned.

At this point, a few photos would help us to identify your carb and make better suggestions.

- Eric

 

Agree with oldcutlass on this. Before you start changing things, you need to know what you have. This site is to HELP people. We all have questions from time to time, and some of us are more experienced than others. Please don't take this wrong, but you do not sound real experienced with a 72 Olds. Again, that is what this site is for. I would suggest you try to learn before you start changing parts. Buy an Olds Service manual for 1972 and read it. Buy a Q-jet book from Doug Roe or Cliff Ruggles. Most people on this site would agree that for street use, a Q-jet, properly rebuilt is btter for the street than any aftermarket carb. And, it will be less expensive to have one professionally rebuilt by an expert, not some guy down the street, than a new carb.

I have a 72 also, that is nearly identical to yours. Mine starts, idles and performs perfectly using almost all stock parts. I rebuild my own carbs and have been doing it since I was 20 in 1970. I wasn't born with the ability, I bought the books and learned to do it. So can you. Welcome to the Olds family, and good luck with your car.

 

I agree about the carb probably being for an 84 rather than a 74 but the 9 is in the position where the 1 or 2 (4 or 5 for California cars) would be. The second to last number is the Division identifier and 5 is Olds, 3 is cadillac

 

Oh. Ooops. I always just ASSume that 3 is Olds.

- Eric

 

Thanks for all the suggestions. I bought Cliff's book and I'm going to stick with the qjet for now.

 

Good luck with your quest. Let us know how it works out.