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Discussion Starter · #1 ·
in the works right now of buying an Edelbrock Performer RPM and a Holley 650 double pumper for $250. My motor is a stock 302. Will bolting these up do anything for performance or will i be wasting gas? i plan to machine the engine one day, but not for another year.
 

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The 650 might too much carb for the 302 unless you are running a lot of power.
 

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Discussion Starter · #3 ·
It's a virgin motor as far as i know. Previous owner put some centerlines with MT n50-15's on the back and some skinnies up front, but i think it was all for show.
Would i have problems with the stock autolite 2100 bolted on the performer RPM intake? I'm not familiar with a 2bbl carb bolting to a 4 bbl intake.
 

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You might be able to get an adapter but I wouldn't see any point in doing that. If you put the 4bbl intake on, you won't get any benefit in you just put the 2bbl on

If it is a stock cam, and still has the exhaust manifolds then I don't think you should go any bigger than a 500cfm carburetor. But that is just my opinion. If you are putting the 650cfm double pumper on (it does sound like a really good deal), you are going to need to put a bit bigger than stock cam in it and you are also probably going to need to put a bigger exhuast on with some kind of headers.

If it is a completely stock engine, when you put the 650 double pumper on you are going to get hesitation and bogging. Won't be fun to drive I don't think.

What are you wanting to do with the car? How is it going to be used? Also, what kind of transmission is in it?
 

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Discussion Starter · #5 ·
I want it to be a good street car, but be able to take it to the track for a couple fun passes. Has a C4 in it now and I plan on having it worked once i get some more ponies in the ole 302.

I'm rather ignorant when it comes to carbs, but am i able to put smaller jets in the carb to reduce the cfm? Is there any way to reduce the CFM to a more ideal setting for my car so that I can use the intake and the carb?
 

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The cfm of a carb is related to the size of the venturi's (the barrels in the bottom). That complicates things. You would have to create some kind of sleeving to go over the top of the barrel (without restricting the butterflies) but below the jets that would restrict the amount of air flow through the venturi's (effectively decreasing your cfm).

But, when it comes to carb size and driveability, you only have to worry about the primary venturi's (the front 2 barrels). When driving under easy to medium throttle you are only really driving on the primaries. The secondary venturi's only come into usage under hard throttle, and that doesn't matter as much.

I hope I'm not losing you because I am almost getting beyond my own understanding of carburetors.

There's is a company that applies the practice of reducing the size of the primaries through the use of nylon restriction sleeves. Click on this link as read a little about it Spreadbore Article. I bought one of these but the carburetor itself doesn't because of a poor job of rebuilding the carb not because of the nylon sleeves. The nylon sleeves in the carb are doing their job of restricting the air flow in the primaries allowing me to have driveablility from a bigger carb on a smaller engine.
 

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250 for that setup is a good deal, but way to much carb for your 302. you could buy the setup and sell the 650, then buy an edelbrock. :bigthumbsup
 

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If I can think of it tonight, I will take a picture of my carb to show you what it looks like with the nylon sleeves in the primaries.

Also, my engine is in a bit of a different category than yours. I have a bit larger than stock cam, and I am running headers. I could get away with a 600cfm carb without the sleevings in the primaries.
 

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250 for that setup is a good deal, but way to much carb for your 302. you could buy the setup and sell the 650, then buy an edelbrock. :bigthumbsup
That is a good thought.
 

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Discussion Starter · #10 ·
Thanks for all the input. I really appreciate the help. I'll let you all know if i end up buying them and how it all works out. I might hang on to them until i throw some headers on and a cam in it. I wish I could do it all at once, but tuition comes first, unfortunately.
 

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Discussion Starter · #11 ·
If I can think of it tonight, I will take a picture of my carb to show you what it looks like with the nylon sleeves in the primaries.

Also, my engine is in a bit of a different category than yours. I have a bit larger than stock cam, and I am running headers. I could get away with a 600cfm carb without the sleevings in the primaries.
I've read that the Edelbrock parts should be used together, so i'll probably go with the Performer RPM cam. I'm a little confused about the headers though. I obviously can't afford and don't need the JBA's, but what's a healthy set of full length headers run? Flowtechs are under 300, but i don't hear good stuff about them. Any suggestions on headers?
 

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Thanks for all the input. I really appreciate the help. I'll let you all know if i end up buying them and how it all works out. I might hang on to them until i throw some headers on and a cam in it. I wish I could do it all at once, but tuition comes first, unfortunately.

you're going to need more than headers and a cam for a 650

I've got a 325 HP at the flywheel 5.0, and I'm running a 600 cfm holley 4160 that's been rejetted, and it's plenty.
 

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They say the parts should be used together but lots of people run edelbrock intakes with Holley carbs. It doesn't make a huge difference.
 

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Discussion Starter · #14 ·
I think i'm going to buy both. I'll hold off on using them until i know exactly what i'm doing with the motor and then sell off what i don't need. Worst case scenario is i don't use either and sell them to get my 250 back.

Thanks for all the help. I look forward to posting some progress pictures once things get underway.
 

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That sounds like a good idea. You can't lose because you are going to at least recoup your money if you don't use them and decide to sell them off. You can take time to research the issue and take time to figure out what you want to do and how to do it.
 

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Discussion Starter · #16 ·
Update:
Just talked to the guy about meeting up to buy the parts. He backed out on the Holley and is just selling the intake for 100. He said his friends talked him out of selling the Holley because he isn't finished with the motor.

Is the intake still worth the 100? They run new for 180 from hat I've seen. He said there is nothing wrong with it, he just switched it out for a Victor Jr on his 347 and it's been sitting in his room since December.
 

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Think I'd just making a plan for the future build and buy parts as you can. the '73-76' motors are the worse to start thowing parts on. They only had 8:1 compression ratio.
Dave
 

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Get the intake. That's a real good deal.
 

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Discussion Starter · #19 ·
First time buying something from a guy on craigslist, so i took a friend (as did he, haha). 100 bucks, got the intake manifold, now i just need to find a decent 4 barrel for a decent price... (back to craigslist)

Thanks again for all the help.
 

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