macarthur

Hey all,

I'm a rookie on the site, but from what I read it seems great! I recently purchased a 1969 Cutlass S convertible with the 350 2bbl and was contemplating having it swapped for a 4bbl. I realize I'd have to get a new intake manifold as well and was wondering what the costs typically would be for such a conversion (i'd have my mechanic do it and don't want to be ripped off)
Would it be possible to buy a new Edelbrock carb that would fit that engine ? Everywhere I looked I could find the Edelbrock intake manifold and couldn't find a 4bbl for 1 '69 350 Rocket.

How much of a difference would I see in the performance ? Any info would be appreciated !!

Oldsguy

Swapping 4bbl for the original 2bbl is one of the first and most basic things hot rodders do and yes it will net you more "kick in the pants" don't know how much hp or torque but unless you are racing it's pretty irrelevant anyway. The reason Edelbrock doesn't list a direct swap is becaus most of their carburetors are square bore like the Holleys and the OEM 4bbl setup was a spreadbore design. If you purchase an Edelbrock RPM series manifold to fit your car (which I know they make) you can get a carb to match very easily and any tech you call on for assistance worth their weight should be able to guide you on the exact model numbers. I am assuming you mean you will buys this from a speed shop or from a catalog like Summit or Jegs. At any rate, your 350 which is a small block will really like that change and respond well to it. Keep the carburetor size to 650 cfm or less, you will have good throttle response and get "fair" gas mileage from the setup although I guess that isn't really a concern anyway. I have an Edelbrock on my big block and like it, it is a good streetable carburetor. Many people don't like Edelbrocks, but they are just as numerous as those who do and those who would prefer some othre brand like Barry Grant or Rochester. I would say you will be please with the change over so do it. Oh, about $350 for the carb and maybe $300 for the manifold, just a ball park figure. Used would be cheaper.

texasred

I totally agree with Dan...except that I'm a Quadrajet (Rochester) guy. When I bought my71 Cutass convertible, it had an Edelbrock Performer RPM intake and Edelbrock 650 on it. Never could get it running to my satisfaction. Many jets and tunings later, I had an aquaintance who specializes in QJets build me one for a little over $100. Ive never looked back. But that's just my experience. Dan's experience different and just valid.

Talk to 100 people and get 100 answers.

C.J.

C.J.

gibbo69olds

Well like CJ said, ask a 100 people and get 100 different answers. I did the same swap you are looking to do on my 69 when I got it. I did however use used parts and my cost was nothing so that may be a trade off here. I switched out the original intake and 2 bbl for an OEM 4 bbl intake with a q-jet carb. I actually suffered less responce off the line and better at high end. Is the tranny a 2 spd jetway tranny? I hope you have better luck than I did. I would assume an edelbrock would perform better. All of the other info they shared I agree 100%. I do have a edelbrock intake and carb on my 455 now and love them. If you want more performance I would suggest upgrading to a Big Block as well. Depending on how deep your pockets are and how much time you have on your hands.

gibbo

ct1979

Anyone ever put a Holley on an olds? I am going to put a edelbrock intake on my 69 Cutlass's 350 and was considering using a Holley because they look so much simplier than Edelbrocks. I have an Edelbrock on my truck, it does well but it took forever to get it tuned right.

murs442

ct1979: My '69 came to me with an aftermarket Holley installed. It was a good performance carb for a couple years, but then the jets clogged and it began to leak at the inlet filter, rendering the car undriveable. After one rebuild and stripped inlet threads on two successive fuel bowls, I replaced the Holley with a correct Rochester QJet. It has never run better -- smooth idle and positive acceleration, hot or cold.

av8tor19330

I put a Holley on my '69 350 but I am putting the Qjet Rochester back on re my expert...No other reason. So now I have this new Holley I'll find some use for

ct1979

Well I did end up getting the q-jet to put on mine. Now I just have to figure how to set all the lines up and choke so I can get it running. Its taken me awhile because I was replacing the exhaust.

skibone

this is a somewhat late contribution to thisthread judging by the last post's date but one of the postees here asked me a question privately and i found this post through his profile...so i'm putting my $0.02 just in case someone might find it helpful nevertheless...

i blew up my liitle 350 rocket early 2006 by red-lining it for too long on a parkway and so i bought a 'crate' 455 to replace my poor 350 [bought the 'high-perf' 455 from some dude in minnesota who advertised on 'chooseyouritem.com...and it was a nightmare and a can of worms but that's a whole different subject hehe]...
a friend of mine did the swap [i'm a quadriplegic so i can't do jackcrap] and the mill now puts out just above 425 hp and 550 ft/lbs...
i loved the qjet on my previous mill but the intake and qjet from my slaughtered 350 never worked very well on that big block for some reason so i finally opened up a summit catalog and after parting with around $750, i had an edelbrock torker 2 and holley 4160 [750cfm - vacuuum secondary/electric choke] carb swapped onto it and that combo really works nicely now...it still peels out hard from idle but more importantly with the new combo the mill picked up some significant 'whoop ***' from around 2000 rpm and above which was sorely lacking with the intake/carb combo from my little rocket...
just relaying my own experience....
))

Oldsguy

Skibone, no problem; thread necromancy is'nt that bad especially when you have good input to add. Probably the trouble with the SBO intake and carb was that it was set up for the smaller engine. I am not surprised that you found a better combination for your BBO though, part of it is matching the parts to the engine but part of it might have simply been new components. I really like Edelbrocks intake manifolds and have never heard anything negative from the performer line except from the racers that it isn't enough because it is dual plane. BTW, the Holley 4160 behaves well for our street/strip cars because of the vacumm secondaries, they give performance similar to the Qjet as far as part throttle acceleration goes because of that. I bet the performance response above 2 grand was due mostly to the intake manifold. Too bad about "slaughtering" your 350, high rpms will kill any Olds engine, they just don't wind up like other V8's but I still love 'em.

skibone

indeed it was prmarily the intake that opened up the mill at higher revs...i talked to some olds dudes at a local cruise and all the hardcore ones who race, unanimously recommended the torker2...the 4160 holley was also a recommendation [couldn't afford anything more expensive so it was deemed best on my budget]...
my ride is truly my drug/shrink/escape so i don't care about the economy despite living on a tight budget..performance rules in my book and i need that kick when i drive it each time...i'm quite happy with its performance now considering it has to remain a dependable 24/7/365 daily driver....
well, except for an overheating problem...but i'm starting a new thread for this so i won't go off topic and perhaps some of you here will be able to help me diagnose the problem...

thanx...