What is the difference from these and the regular HP carbs... or a street avenger for that matter?

Casey,

I can't find any info on a Holley HP Street. Is this brand new? The HP Pros all seem to be geared exclusively to racing, while the Street Avengers are very definitely a street carb. According to Holley, the Street Avengers are already sized and calibrated to work in a specific horsepower range, and have all types of very easy to tune features. Two different places identified the 670 Street Avenger as a good carb for my ZZ4, so that's what I have.

In the new summit racing catalog, on page 16, there is the Holley Street HP Carburetor.


It's easy to install, customizable, packed with features, and it'll look so nice sitting on top of your new engine. It's Holley's Street HP Carb, and here's what it's got in store for you: contoured venturii for increased airflow and more power, street/strip calibration for outstanding throttle response and drivability, and all necessary vacuum ports for easy street vehicle installation. It also features 2-corner idle circuits, quick-change vacuum secondary springs, and a F*rd kickdown linkage. The tumble polished finish is pretty cool, too.It's 750 cfm and the part number is 0-82750

$499.95

The only difference I see is the "contoured venturii". How much of a difference can that make? Anything else difference about these carbs?

EDIT: It also looks as if these have no choke either.

I found it. FWIW, I would spend about $100 less and get the Street Avenger 770. It looks like all you get with the other is less features. Just my .02 worth.

The HP street carb is a vacuum secondary carb. I really wouldn't call a chokeless carb streetable though. The regular HP's have 4 corner idle, no timed spark port, double accelerator pumps, etc. It looks like they are trying to use the image of the HP without the features of the HP.

Where is the timed spark port and what does it do? Is it that little itty-bitty port on the left side of the carb (if you are standing infront of the hood, looking into engine bay), that I plugged with a very small vacuum plug?
And how would a HP series differ from my current carb, a 4779 with a 850 baseplate, milled choke horn but retains the fast idle cam, 4 corner idle, nitro floats added, your basic double pumper setup..? The dumb car actually starts easier with the choke horn off no matter who tried to set it. I have always eyeballed the 950HP for my motor, but I am curious of what makes it the "HP" ?
Is it just a chokeless DP? Or? The little blurbs in the magazines don't say enough and I learned more about my carb just my reading the like 2 page manual that came with it from holley than anywhere else...

Matt