is 650cfm enough?

On a basically stock 383 with manifold heat the 650 dbl pumper will be good choice. Stick with 68-70 jets frt and no more then 76-77 rear the pump shooters are good as is in most cases unless the car is heavy. I try to tune at the track with that issue. Don't start screwing with the air bleeds unless the car is modified or you cannot get it to run right, or you got the dough to blow on th cost of the carb

If you're keeping the stock intake a 650 Holley will be about all the intake can use. Back in the day I'd go to the drag races and look at the carbs on the cars and they were much smaller than I would have guessed. These weren't bracket racers, they would have run a bigger carb if they could. But obviously the slightly smaller carb gave better ETs.

If and when you get your "new engine" figured out it will be time to go bigger on the carb. But you have to realize that 383s came stock with carbs that weren't much bigger than 500 cfm. It used to be that putting on a 440 carb would help out quite a bit, and those 440 carbs were in the 600-650 cfm range.

I can see some big corks in your engine's performance and the carb ain't one.

R.

Not the best example but my buddy has run a 650DP on his 55 Chevy for years, it's a 427, turbo 400, 4:56 gears, 9x28 DOT slicks, he drives the car quite a bit & around town the small carb really helps drivability, at the track with the 650 he's run consistent 12.0's... With a 850 & lots of tuning he's run a 11.92... Personally I think a 650 would be fine for a healthy 383....

Many people overcarb...I've run a 12.40 in my Duster with a stock stroke 340 and Holley 650 carb.

Jerry as has already been mentioned, most people tend to overcarb their engines, particularly street engines. For what I presume you're planning to do with your car the best thing you can do is go on the small side for a carb. You'll find it to be more responsive, particularly at low rpm's where you're likely to be spending most of your time. The reality is 6500-7000 rpm runs won't be happening so much for you that you'll miss the extra capacity.

I've been through this myself many times over the years, and in each case have found myself happiest with a street car running a 600-650 cfm vacuum secondary carb. I'm partial to Holley's myself. I've struggled with a few Edelbrock's and AFB's. I think the Holley's are easier to understand, particularly for an idiot like me.

Realize you're not talking that much money that you can't upgrade later on when you re-do the engine. There's always a good market for used Holley's. Once you've done the top end work, sell yours and go for a 750.

This car is my 71 challenger vert driver. i've got a built 440 going into my 73 for when i really want to get on it and go. so for the driver i was thinking the 650 would be fine as well, figuring it would be close to what the factory used. when i do rebuild this it won't be much more than 450 hp or so and i don't plan on racing it as thats why i'm building the 73.

Buy it. Something to keep in mind, the 650,700 and 750( 4777,4778,4779) all have the same size throttle plates. If you decide you want a bigger carb later, swapping to a Proform or Holley main body makes yours a 750. Those main bodies also have removable air bleeds. IIRC, changing the primary metering block is a good idea if you swap to the bigger main body. I believe the emulsion tubes are different in most of the 650s.

The 650 will run fine.It will give great low end and midrange punch falling off slightly on the top end.Buy it and try it.
A well tuned 750 vacuum secondary would be better for overall performance but not a bit better on driveability.

I have a 650 DP on my warmed over 383. I also have a 750 DP which has been rebuilt by the guy who did the 650 DP for me. For some reason my car loves the 650. With the 750, it's harder to start, and just seems "off." Put the 650 back on, and she's ready to burn the tires off.

AMEN pro 650 guys. Bigger is not always better.

i'd get the 750.

I bet it will run better with the 650 than it will with the 750. Stock convertor, stock cam.

Sheldon

you didn't mention your manifold but either way a 650 on a 383 auto car is pretty sweet.

You guys are nuts!!! Drop a 1050 Dom & don't look back...............



JK, the 650dp will be fine.

right now the engine is all stock including the cast iron 4bbl intake. i would love to build this up as a "FAST" style engine build but i don't know if its in the budget. so most likely its going to get a mopar 528 mechanical cam and true flat top pistons and have the heads ported, but keep the stock sized valves. again i'm not looking for all out race performance just a good driver thats got some power under the hood. i think about 450 hp will be plenty. i don't see this engine revving past 5500 any time soon either.

and yes its an auto with a stock converter but i will change out the coverter once i get the engine rebuilt. and the trans will get a shift kit just firm up the shifts some.

My friends 440 made quite a bit more power than it oughta... had pretty good top end too... that was a Holley 670 Street Avenger that i tuned for him. My 440 was the same way... junk that ran like a built engine... that was only a 750. That 650 with a solid tune should be fine, especially for what you're after and with what you have. When the time comes and you need more, if you're a tuner, you can get quite a bit more airflow out ov that 650 even. There are quite a few lil tricks that will net you more CFM and you can get into the 700's without buying a new body or carb... yet, you'll still have the small-carb driveability. My friend's 440 always did daily-drive a bit better than mine did.

I've always been a fan ov doing the most you can with the least. Anyone can dump on an 850DP and run, but the car will like the smaller carb almost every time, and in many cases run quicker anyways.

All that said, if you happen across a nice 750 i'd pick it up... but theres no rush to do so.

Had a Holley 670 Street Avenger on my '68 road runner with an old Edelbrock DB4 intake and a Comp Cam and stock exhaust manifold and Ultra Flo's.....BEST combo I ever had...changed the PV's up one size and drove it and drove it and just a no hassle turn key set-up. Liked the Holley 670 so much on the 383, when I got the '69 GTX 440 I put a Holley 770 SA on it right away...same result "plug and play"

Go to Advance Auto and order the Holley online and you save on shipping and usually there's discounts on over a certain amount purchase or most of the Adv Autos will price match even places like Summit's price and as I said no shipping charges. There's also links to Advance Auto discount codes/coupons.

I just bought a proform 750..dual feed/double pump/electric choke/bowl sight glasses,easy air bleed change for 439 delivered. 750 will run well on your 383 and even better with the future mods mentioned