[68 redcam]

hey guys what is your opinion of correct carb size .78 350 stock bottom end .sr torquer heads 202/160 valves .comp.cam xe 274 cam. weiand intake.m-20 4 speed. 308 gears.in a 68.running a 650 spread bore double pumper .i know its to big .it will burn your eyes at idle . jeff

 

[68 redcam]

oh yea the heads are 67cc jeff

 

[JohnZ]

Actually, the CFM is about right - probably just needs a rebuild and sharp tune. The idle mixture screws determine the idle rich/lean condition (assuming the throttle plate isn't too far open, exposing the transfer slot), and if your idle air bleeds are clogged (usually due to running no air cleaner), it'll idle rich regardless how the mixture screws are adjusted. Get a genuine Holley rebuild kit for it (not a generic parts-store rebuild kit), spend an afternoon doing it, and you should be in business. Get the list number off the front of the choke air horn so they can get you the right kit for it.

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JohnZ
CRG
'69 Z28 Fathom Green

 

[c4boom]

ya befor i got to the part about the carb i was thinking 650

 

[Posey Racing]

I agree...that size is in the ballpark. rebuild and tune should do it!

 

[rodsters]

Try this website, but 650cfm is probably correct.
http://www.prestage.com/carmath/calc_CarbSize.asp

 

[Go69]

Be certain to check/replace the power valve as these pieces are the culprits for the conditions of which you speak.. Running rich, burning eyes, bad hesitation, poor mileage and the like can all be traced to a blown power valve-in addition to other things. I don't want to sound like a P/V will solve all Holley tuning issues but this is where a lot of them start and end-in addition to float level.

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1969 Camaro SS 350-383ci./365HP, T-56, 12 bolt, Power Trax Locker, 3.73 gears, 4 whl disc, Deluxe black houndstooth interior, rear window defogger, tilt steering, floor console w/gauge package, center mntd. clock, tachometer