Intake and exhaust on 1968 289 2bbl
 

I have a 289 2bbl automatic on my 1968 coupe. I have a stock 4 bbl intake with a Carter 625 cfm in the garage that I would like to put on it. When I started talking about dual exhausts, my friend asked if I was changing the cam. I said "no" and his reply was "If you're not changing the cam, the single exhaust (2") will handle it, especially if you put a Series 50 Flow Master muffler on".... is he just pulling my chain, or is he legit?

Hi,
It has widely been accepted, the first mods most enthusiasts will add is a 4 barrel, dual plane intake and dual exhausts. These are the initial "given" mods. Where the "rub" occurs, is in the size of the carb. I think you'd do better with a 600 or slightly less, if buying for the first time. However, since you have that 625 setting around, then clean it up, check the float levels, give it a shot. Dial it in using a vac gauge. Experiment with advancing your initial timing a couple of degrees. ....and for God's sake, keep a log of your settings and adjustments!
Your engine will benefit from what you have in mind. The choice in "muffs", is just that, a choice in the sound and Db level you're comfortable with. A great place to check them out is a car show or cruise night.
Hope this helps!

Does size matter
 

I agree with the previous reply posted and I too believe that the 650 CFM is a bit big based on my 351CI .030 over edelbrock 4bbl and aluminum intake, but use the carb calculator at the WWW provided below:

http://www.gtsparkplugs.com/CarbCFMCalc.html
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