It's been ages since I hotrodded a carburated engine, but I used to go
20% higher.  So given your numbers above, in the olden days I'd have
gone for 1100cfm or two smaller double pumpers.  Fuel injection systems
have gotten so much better these days that I just don't find it worth
the hassle to use a carb anymore.

Good luck!

Cheers,

    f.ck me thats one fugly car. Why not put Osama's head on the side with
a big bullseye on it?

I agree that Holley ought to use the same vacuum to rate all its carbs.
1.5" Hg has been the standard since forever, and they ought not to
change it, at least not without making a prominent disclosure,
regardless of what the competition does.  It wouldn't be hard to make
that disclosure.  The people who are into building their engines and
who care about cfm aren't idiots (e.g., unlike the Prius owners who are
getting all hissy to find out they only get 40 mpg highway and that
their electric motors and battery packs just become excess weight on a
highway trip.  (Wait till they find out the battery packs cost $6000,
when they have to replace them in a few years.)

Regarding the reliance on a computer program to choose a carb, though,
you've got to keep in mind that actual cfm depends on actual  vacuum in
YOUR engine, which may or may not be 1.5" Hg.

When hotrodding a car you've also got to keep in mind the slogan "speed
costs money, how fast do you wanna go?"  This applies not  only to the
upfront costs of the "perfect" combo, but also for the costs of broken
parts and parts that were not optimal and parts that went on the shelf
when you decided to go in another direction.

There's  a really great article about carb boosters in the next most
recent Popular Hot Rodding -- in fact they've got it up on their web
site right now:  http://popularhotrodding.com/tech/0511phr_carb/ In a
nutshell, the author David Vizard states that you should generally
choose a carb with excess cfm, because you can tune it to your cid,
heads, cam, etc., with the booster.  It's the booster that introduces
the fuel into the air, and it's the booster that determines both low
speed driveability AND peak hp.

In fact, everything that David Vizard has written for PHR lately is
great stuff.  The first one I saw was about maximizing  compression
ratio.  There was another one, more recently, about zero loss muffler
and  tailpipe systems.  See if you can find them on the PHR web site.

180 Out