My observation is that the "rating" of carbs at "X" cfm is relatively new. The old carbs were not so rated, or at least publicized. A 413 cubic inch engine at 5,200 RPM would gulp about 621 cfm at an unlikely 100% volumetric efficiency. Thus, a couple of 350 cfm carbs would seem to adequately feed the engine. Bolting a higher cfm rated carb onto the engine does not increase it's free air capacity and probably not work too well at lower speeds. I'm willing to learn here from the automotive engineers and specialists. I mainly worked with gas turbines and natural gas-fired engines with fuel injection. C-300-ly, Rich Barber 1955 C-300 (498 cfm FAC @ 5,200 RPM) -----Original Message----- From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Sean Duggan Sent: Monday, June 04, 2007 10:55 PM To: chrysler300@xxxxxxxxxxxxxxx Subject: [Chrysler300] AFB Carbs Does anyone know what the CFM rating is on the dual quad AFBs. I wanted to know for the H carbs, 3258S and 3259S, but I am curious about all of them, 2798S, 2799S (300E), 2903S (300F&G), and the 3505S (300J&K ram). I've looked all over for information but I can't seem to find any. Thanks, Sean Duggan Los Angeles [img]http://i90.photobucket.com/albums/k265/saduggan/300front.jpg[/img] To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/ Yahoo! Groups Links To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: mailto:Chrysler300-digest@xxxxxxxxxxxxxxx mailto:Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/