Carb replacement

Discussion in 'Holley' started by Bigmarc650, Aug 23, 2016.

  1. Bigmarc650

    Bigmarc650 Well-Known Member

    Gentlemen, I'm replacing my stock Rochester 2 jet with a holly 2bbl carb. I got it home today and realized I need an adapter to mount this bad boy. It would've been nice for the dude to tell I needed an adapter before I left the place (I'm about 30 miles away). My question to you all is what other tidbits of info will I need to know for changing this thing out? It already looks like I'm going to have to change out the fuel inlet hose, hopefully I can find one that works soon. I'm on paternity leave and trying to get this done in like a week. I didn't know after spending that kind of money on the holly that it's not just be plug and play. Any help Gould be greatly appreciated. Thanks.
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I would have just had the Rochester rebuilt and avoided the problems you are going to have. Maybe this adapter will work,

    The only other problems should be fuel line and throttle cable connections.

    DEADMANSCURVE my first word : truck

    so , its probably a 7448 ( 350 cfm ) or a 4412 ( 500 cfm ) . manual choke I take it . a loooong time ago I put a 4412 on a sbb 300 - worked fine . I've been doing a few rebuilds on 'em lately - local dirt track n derby guys like them . if you have a napa or advanced auto closer a lot of them can round up what ya need . look for a grey haired counter person !
    several inlet choices , basics or AN style . its pretty much the front half of a standard holley 4 bbl so the usual parts are used on it . nothing weird . do a preliminary float setting and idle screw adjustment , fuel hook up , linkage hookup , turn the key . see how it goes .
    edit : yeah , a quickee Rochester rebuild would have been easy . and there's mod's you can do to them . there's larger ones too ( like maybe 435 - 450 cfm ) , although I can't quite remember if the larger ones will bolt onto the smaller carbs pad ? I'm kinda thinkin maybe not .

    Attached Files:

    Last edited: Aug 25, 2016
  4. doc

    doc Well-Known Member

    I just take a 1/4 '' thick piece of steel and a base gasket and make my own adapters,,,, and like already said you will have to change the fuel inlet tubing and linkage set up,,, I would still rather have a holley.... once the fine tuning is done it will run good....
  5. Bigpig455

    Bigpig455 Fastest of the slow....

    Doc! Is that really you?
  6. doc

    doc Well-Known Member

    Yep,,,,, it really is..... :eek2::eek2:
  7. Bigpig455

    Bigpig455 Fastest of the slow....

    Expect a call, Chief!
  8. doc

    doc Well-Known Member

    OK,,,, I will be in church from 8;30 to 11;00 ,,,,, any time after that.....:grin:
  9. Bigmarc650

    Bigmarc650 Well-Known Member

    Thanks again for your advice gentleman,
    I got it hooked up and it seems to be running pretty well other than some hesitation at take off, (not sure that it's a carb issue or maybe timing?) and an annoying whine that is coming from the carb. I've looked and can't seem to figure out where its coming from. It's a distinctive screaming the thing is doing, to where I can hear it while I'm driving (and so can other drivers). it's consistent until I get on the gas and even still a little while I'm driving at low speeds. A little help would be greatly appreciated.
  10. techg8

    techg8 The BS GS

    you can get a whistle like that when air sneaks past a basegasket. make sure its sealed down.

    Some carbs also get a whistle down near idle that goes away as throttle is opened. This can be caused by air passing the near closed throttle blades and moving over an opening in the baseplate, typically a ported vacuum hole or something like that. you can scuff the edged of the hole to reduce or eliminate this whistle.
  11. telriv

    telriv Founders Club Member


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