Mopar 383 carb predicament

[Lewis]

Hello all,

2 years ago I purchased a 73 charger 383 727 from the USA and imported it to the uk, I have been on and off fixing it and have got to the point I can drive it, previous owner told me it had 400-450Bhp but I have never dynowed it so I don't know what it truly has, it was rebuild before purchase and it has a edelbrock performer intake 906 heads blue anodised roller rockers and a hydraulic flat tappet cam dual valve springs and some unknown brand of headers, other than that I don't know what parts are inside, i have spoken to 5 people about what carb I should get and they have all said different size cfm I'm after a double pumper as I won't be driving it much so not worried about mpg, what size cfm would people suggest I get? I have a 600cfm and a 850cfm laying about which I have been given by a friend so before I spend money making them either of the work, I would like to know what people's opinions are, is one of them okay? I would appreciate the help as I'm being told so many different things over here I don't know what to do, and because I have to get the majority of parts in America I don't want to lose money on the wrong carb thanks Lewis

[John_Kunkel]

Of the two you have the 600 is the most practical, the 850 is too big IMHO.

[XH29N0G]

You will likely get suggestions from 600 to 750 cfm.  I am told there can be a difference in how the car responds and feels.  I experienced this with a bigger motor and bigger carburetors and became a fan of those on the slightly smaller side because they had a crisper throttle response.  In your case, my guess is the sweet spot is somewhere in the 600-700 range.  The exact fit will depend on how you drive and how you have the car set up.

[Lewis]

Thank you both ever so much for replying, what I'll do is fix up the 600 and go from there then I really appreciate the help, being in the uk I can't seem to find many people that have experience more than there first car, once I have the 600 completed I'll post back and let you know how I get on and how it responds

[XH29N0G]

There are also various ways to calculate ideal carb size.  One is at http://www.wallaceracing.com/intakecfm.php