carb CFM

[jayb]

That carb comparison (Blair's special 4150 vs. the 1150 Dominator) did actually make my book; graph on page 226.  The carbs were very close, but the Dominator came out a little ahead.  This was on a port matched Victor with the Dominator bolt pattern, so an adapter was used to fit the 4150 carbs (Blair's carb and a Barry Grant 1000 carb) on the manifold.  I suppose that may have colored the results a little, but in any case the carbs were very close.  Also of note is that on the Victor that Joe Craine ported, which had the 4150 bolt pattern, Blair's carb beat all the others that were tested, which included the Barry Grant carb, a 1050 Holley 3 barrel, and a Holley 1000 with annular discharge boosters.  That carb/intake combination also made more power than the stockish Victor, attesting to the value of Joe's porting job.

[bsprowl]

The old Holley three BBLs came in two sizes, 950 and 1030 CFM.  The smaller  (@950 CFM lol) used the standard booster venturi on the secondary side while the larger just used two bass tubes.   

I loved them as their vacuum secondary was forgiving if you went to wide open throttle too early on the street where a double pumper would stall. 

[FE Jonny]

It definetlly is relative to desired RPM use, I have run an 840 CFM carb on a 380 cube engine with big heads and it ran great. I have also run a 650 CFM carb on a 460 and it pulled great due to the tiny head ports on the stock 385. I would size the carb to the rated CFM calculated by your intake and cylinder head CFM, that is going to get you the best idea of where you want to be, but if you want to drive in mid range RPM most of the time go somewhere in the middle.