70-f400 - I am not sure if my existing carb is 2 or 4 barrel. I only know that it's been worked on before by a carburetor shop. Most of the repair history files on this car were lost at my mother's home at some point. But it was my mom's car and she bought it from the factory. She said she had the carburetor worked on. I would really like to buy new parts. I have five older cars and I am at the point where if it's not a 'no longer manufactured part' which is not available new, or something that I'm forced to have a machine shop make for me at high cost, then I will buy it new in order to minimize problems. That being said I sell used car parts online as a part time job, so no offense intended (I need people to buy used parts from me, otherwise I go broke LOL). But you know what an intake manifold is a solid peice of metal, and unless it's been worked over by a machine shop than a piece of metal's a piece of metal, right? But on the other hand, why take a part which is stock and ruin it, when I know for a fact it was original to my car. Plus machining intakes and cylinder heads is a black art, with no real provable results unless you hook up your intake to a machine before and after and have it flow and pressure tested, which is something I prolly can't afford.
I did read an article from high performance pontiac magazine which discusses later model mid-70's aftermarket versus stock intake manifolds though, and it talked about how people weren't getting much better airflow from aftermarket intakes, even though the stock one looked like it left much to be desired. I didn't know if the same applied to 1970 models or not, because I'm not knowledgeable yet about the generations of Pontiac, and what parts are inter-compatible by chassis and/or generation.
After reading your post and doing a search, I see that Quadra-Jet refers to Rochester brand. I have only heard of Edelbrock and Holley and Weber, however even though I haven't heard of Rochester company, I have heard the name Quadra-Jet or Q-Jet being thrown around before. So is that a well-known aftermarket carburetor for the 1970 firebird that would be equal in quality to, say an American or Euro made Weber or and Edelbrock? Years ago I used to have an Edelbrock magazine with a lot of parts for my car, back when I had no money and big dreams. And there were a lot of parts listed for my 1970 firebird. But now the Edelbrock website barely lists things as compatible with specific years.
By E-carb, do you mean one that has smog control parts on it? Because in California, cars before 1976 don't require smog parts on them, or even a smog check or test. So I will definitely be avoiding those parts. I secretly remove EGR components from my Mercedes cars, and I also replaced my exhaust pipes on one of them, which had a catalytic converter, with a 'Euro model' downpipes which had the 'pre-cats' on them. I had a muffler shop chop off the pipe right before the pre-cats, and gut out the honeycombs inside, and then re-weld it back together, and then I had the downpipes coated down to a certain point (very expensive process) with a special ceramic coating, so that the smog shop can't even tell the difference. Anyways these days I pay a smog guy to do my smog, ever since the requirements went up a couple years ago, so it's no longer relevant.
NOT A TA - from your user name and pictures, I can tell your 1970 firebird was an Esprit or 400, and now you are putting on the TA spoilers and making something awesome of your car. Good for you, man. That was my dream back in the day when I had no cash and a 'Year One' magazine. I selected all my parts that they sold in the magazine to convert my Firebird regular orbit orange car into a trans am. But then my mom looked at the the list and the price and laughed at me. She said I'm lucky she's paying my insurance and half the price of gas. Nowadays I have some more cash, so you never know I might have my car on jack stands for a while and see what I can do.
OK, thank you for the advice. It sounds like Rochester Quadrajet or Edelbrock Performer (but not Performer 'RPM') is the way to go. I didn't find the 575 Speed Demon on the Edelbrock website, but I will look into it. And I will definitely avoid a large flow carb such as a 750+ CFM. Thank you
ponyakr - Does my car from the factory have an iron intake manifold? That seems much heavier in weight than the aluminum of the Edelbrock. But if there's no noticeable difference in airflow, why even bother, right? Other than maybe you want to replace the intake manifold gaskets and refresh the mounting bolts, so you might as well swap the manifold at the same time, right? Who knows maybe I should buy the Edelbrock, do the aforementioned, and take my stock intake to a machine shop and have them work their magic on it. Maybe they can make it flow better than an aftermarket intake.
Also noticed I was mistaken to put manual transmission. The car has an automatic transmission unfortunately. So I will now know if I buy a Q-jet, to buy the additional bracket for the kickdown cable (I believe the Edelbrock version of this cable is part #8015 (
http://www.jegs.com/i/Edelbrock/350/8015/10002/-1). Is that what you're referring to?
Yeah when I saw the black coated Edelbrock intake, I thought that was the bee's knees. But I'm not married to any one brand. I just have this sense that the intake and carb should be of the same company if at all possible.
