hillsglass
Active Member
I have a 383 ,30 over with 440 six pack cam. I was told to put a 850 edelbrock on it , I think it s too big.What does everyone think? It has 3:55 rear
carb question
- Thread starter hillsglass
- Start date
moparbob71.2
Well-Known Member
On my last 71 RR I had a similar 383 that the PO had put a 750 cfm on it. It puked fuel out the tailpipe, couldn't start it in the garage. I put a 670 on it and it ran perfectly, good throttle response. Car was a 4speed with 3.55. Hope that helps.
Bob
727
Well-Known Member
Got a similar set up in my wife's Belvedere. 400 6 pack cam and Edelbrock 750. I think the 850 would be a bit much.
The 750 is just right. I did have to reduce the size of the accelerator pump squirter nozzle to a #23. That did away with the dead spot everybody complains about when referring to Edelbrock carbs.
The 750 is just right. I did have to reduce the size of the accelerator pump squirter nozzle to a #23. That did away with the dead spot everybody complains about when referring to Edelbrock carbs.
Ranger16
Well-Known Member
I've got an Edelbrock 750 on my 383 (3.23 rear end). It ran just fine, though a bit rich, but after leaning it out a couple of steps it doesn't smell rich anymore and gets about 16.5 on the highway.
lewtot184
Well-Known Member
the 650 or 750 edelbrock will work. the 650 is nearly identical in throttle bore and venturi size as the original 383 carb. the 750 would work fine, even with a stock intake, but is jetted fairly rich. down sizing the 750's jetting is fairly simple. the 650 would probably do fine just as it comes out of the box.
PurpleBeeper
Well-Known Member
I agree with the 3 posts above. A 750 vac. secondary was about right for my 440, but is a little too big for a 383 in my opinion. No way I'd run a 850 on a 383 unless it was a track-only car.
747mopar
Well-Known Member
If it's going to be a street car I'd go with a 750, I'm sure an 850 would work but you'll give up some low rpm tuning. I ran an 850 on my 456 for 2 years and loved the performance but idle and off idle was always a challenge but still decent, the new 750 is a dream to drive throughout the rpm range with any issues at all.
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hillsglass
Active Member
Thanks for the great info I will try the 650
GTX MATT
Well-Known Member
DON'T buy a 750 Eddy. They don't make an 850. Get a 650 AVS or 800 AVS if you want an Eddy, and get it with manual choke.
800 would be a little big, you've got a stock 383 HP from the sound of it. If you have headers and an Eddy RPM I might go with the 800. If its stock intake and manifolds the 650 will work nicely.
800 would be a little big, you've got a stock 383 HP from the sound of it. If you have headers and an Eddy RPM I might go with the 800. If its stock intake and manifolds the 650 will work nicely.
rumblefish360
Well-Known Member
Hillsglass, I agree with GTX MATT!
I have not been a fan of the 750 much. Mostly since it is an AFB model. I so much like the AVS style carb better. Wjile my 750 AFB worksvery well on my 360/4spd car, I do like the adjustable secondary spring loaded door on the AVS models a lot better.
I have to ask though, why a manual choke carb instead of a automatic electric choke? There is a "ZERO" performance gain on a manual choke carb.
THANK YOU! I'm reading the replies of everyone saying "850 Edelbrock" with amazement since they do not make an 850 carb!!!!
I have not been a fan of the 750 much. Mostly since it is an AFB model. I so much like the AVS style carb better. Wjile my 750 AFB worksvery well on my 360/4spd car, I do like the adjustable secondary spring loaded door on the AVS models a lot better.
I have to ask though, why a manual choke carb instead of a automatic electric choke? There is a "ZERO" performance gain on a manual choke carb.
lewtot184
Well-Known Member
i've read a lot of negative comments about the 750 edelbrock thru the years. sooo, i found a $40 one at a swap meet. took it apart, looked at and measured everything (air bleeds, idle jet, etc) i could. the only major thing i could find wrong was the primary jetting. they are just stupid rich (800's are just as bad). it would be nice if they had .101" needle and seats but thats not a deal breaker. i think the real problem is peoples lack of tuning skills or they are afraid to just get in there and change stuff. very few carbs are perfect out of the box so to me jetting is just a norm.
GTX MATT
Well-Known Member
I say manual choke because I assume the OP wont tune it much. The electic choke Eddys come jetted a bit lean, which is further exacerbated by ethanol blend fuels that need to be run a little richer for best power. The manual choke setup will probably be closer OOTB, especially on a 650. The 600/650s seem to be the leanest ootb.
GTX MATT
Well-Known Member
I know you're a pretty good tuner, did you ever run the carb on anything back to back with another carb?
lewtot184
Well-Known Member
i haven't run the carb. i did do a lot of comparisons to a 4618s avs (same size throttle bores and primary venturi as the 750) i run on my '69 r/t. i actually used some of the 750's specs on the avs and the carb drives great. i firmly believe there's a lack of understanding with these afb type carbs. i think folks want to apply holley tuning norms to these carbs and sometimes it just won't work. a for instance is primary idle air bleeds. the holley has one, the afbs have two (if you don't count the economizer bleed and emulsion tube bleeds). i'm just not buying these carbs are inherently bad; just not calibrated the best. the 800avs is calibrated just as bad but is a good performer once sorted out. i don't recommend the 800 for a 383 street car because of the large primary venturi.
Ranger16
Well-Known Member
Needles & seats are cheap and easy to change on the Eddy. You don't even need to dismount the carb. Their simplicity is one thing I like about them.
I thought mine was jetted rather rich which is why I leaned it out.
Supposedly the manual choke models are for " performance applications", and are jetted richer (slightly). A properly set electric choke will get you there, and I prefer the AVS series. Although the Performer ll series has an annular booster which should eliminate some transition stumble/lag - sounds interesting. It's only available in a 600 for now anyway.
Agree w/Lewlot on the 800 AVS for a 383, primary venturis too large, super rich OOTB. I have a brand new 800 AVS with 2 hrs on it I'll be posting For Sale soon, customer went Holley because "just didn't like it"- hence trying to tune it like a Holley.
Agree w/Lewlot on the 800 AVS for a 383, primary venturis too large, super rich OOTB. I have a brand new 800 AVS with 2 hrs on it I'll be posting For Sale soon, customer went Holley because "just didn't like it"- hence trying to tune it like a Holley.
lewtot184
Well-Known Member
i've worked a lot with a friends 800avs on a 427 chevy. jetting down really cleaned it up. down sizing the pump squirter and cleaning up the casting flash around the pump well was a very noticeable help at low rpm. the engine performs well with the mods and upped fuel mileage. i just don't understand why these carbs are calibrated so rich out of the box.
rumblefish360
Well-Known Member
440/454/455 cid performance engines
Smaller need it reply. LOL
Smaller need it reply. LOL
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