swapping carbs on 383 - Edelbrock to Holley - whats needed?

Engine, Transmission & Driveline

  1. Blackmopar

    Blackmopar Member

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    Guys,
    Its a rather long story but Im wanting to swap carbs for a few reasons this evening after work - I have a 650 Holley that's been previously set up for a chevy that I want to try on my 383/727.

    Im currently running a 750 Edelbrock. I had to get a specific linkage adapter for the Edelbrock.

    Do I need a linkage adapter to run the Holley or anything else besides a new gasket?

    thanks
     
  2. commando1

    commando1 Old Man With a Hat on the Porch FCBO Gold Member

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    I am under the impression that the Mopar throttle linkage adaptor from your Edelbrock can be used on your Holley.
     
  3. Blackmopar

    Blackmopar Member

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    well dat'd be convenient....for once! haha thanks Commando!
     
  4. 70bigblockdodge

    70bigblockdodge Old Man with a Hat FCBO Gold Member

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    Your fuel mileage will probably suffer.
     
  5. Landyacht

    Landyacht Active Member

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    Whats the long story?
     
  6. 1978 NYB

    1978 NYB Warfighter FCBO Gold Member

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    Do you currently have an Eddie 1406 on your 383?
     
  7. Blackmopar

    Blackmopar Member

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    1407 - manual choke - not hooked up. plan to run a 650 vacuum secondary - no choke

    long story is i bought the 1407 and installed it with a weiand dual plane - after chasing fuel issues (unrelated) it has been running well - although could be better. Yesterday after checking and resetting idle speed/mix I took it out for a stomp. performed well until coming down a slight hill off throttle to a stop - idle speed dropped real low and cutout. Try to restart and no fire. not even a stutter. to the point Im thinking no spark - ruled that out. fuel pump is bringing fuel to the party. at WOT I can get it to start - barely. but rough stumble and will eventually stall. Slight gas leak on driverside under throttle linkage that has shown up only with this problem. pretty sure Ive got a stuck float(s) possibly a bit of crud from previous fuel issues - although running 2 filters - before and after pump.
    Anyway - I figure Im getting into the edelbrock, but Ive got this holley just sittin there - some have suggested 750 is too much on a stock 383 - although Ive had a 66 bbody in a previous life and ran like an ape witht eh 750

    Im just curious the holley might comapre.... is the short story....HA
     
  8. Landyacht

    Landyacht Active Member

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    Could be a stuck float or improper float adjustment. Too much fuel pressure might also cause it to leak. Make sure you are running no more than 5 or 6 psi pressure. I would also highly advise using an extra thick carb gasket. Those thin gaskets that come with the carb can cause vapor lock due to the heat from your intake boiling the fuel in your float bowls. I had a vapor lock issue with an 800 cfm Edelbrock that would cause my car to stall. Using a thicker gasket solved my problem.
     
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  9. Blackmopar

    Blackmopar Member

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    mechanical fuel pump - don't have a pressure gauge in line, but tested when installed and was 3.5-5 lbs.

    Thanks for the tip on gasket - I thought this might be vapor lock, but the symptoms were still there the next morning and evening after the car sat in a liquor store parking lot

    the 1407 was bought off the shelf in January and has been on the car since - no mods or adjustments - but will be removing top plate and cleaning/checking adjustment on the floats at this point

    But I figure Ill try the Holley since I don't have another car to put it on - will report both findings when done - thanks again
     
  10. Blackmopar

    Blackmopar Member

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    FYI - while it could be modified to work - the two brackets are different. Since Ill likely go back to an Edelbrock at some point Im not going to afro engineer it. Waiting on a stupid $9 part again....To show the difference - Edelbrock on top/ Holley on bottom

    Edelbrock 1481.jpg

    Holley 510-20-7.jpg
     
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  11. MarPar

    MarPar Meat Man with a Hat FCBO Gold Member

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    stupid $9 parts!! :mad_6:

    and yes, please properly engineer things...:eek:ccasion14:

    as has been mentioned, I reckon a stuck float or too much pressure. or both.
     
  12. saforwardlook

    saforwardlook Old Man with a Hat FCBO Gold Member

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    If it is an original Holley, not an aftermarket one, I would say it very likely will not run worth a crap. If it is an aftermarket, maybe it would be OK.
     
  13. Blackmopar

    Blackmopar Member

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    its an original Holley that has been reworked - Ive always run Carters and then Edelbrocks but I do have buddies that have great success with Holleys.

    I don't want to get into a debate on what carb mfg is better - they both make better carbs than me. And since I have this one sitting on the bench it seems like swap and play is a good idea.

    Since this motor is completely stock (aside from a dual plane manifold and carburetion) I suspect I may have too much carb with the 750. I believe the stock TQ carb was a 600 and maybe running the 650 vacuum secondary could be a sweet spot.

    I have used 750s on 383 in past with great success, but those cars also had upgraded spark, headers, and mild headwork.