Re: Why Spreadbore Holley's Don't Work?
I've run both the 6210 and 6211 on various combos for the last 30 years or so.
It's always amusing to see people who have never had something, bashing on it.
Not sure where the "nothing but trouble" comment could possibly have come from; they're typical stock-ish Holleys, with side-hung bowls and a fuel transfer tube; just yerbasic street carb. The only significant difference between them and a square-bore side-hung 4-bbl like alot of the Frod and Xler stock ones in the 60s, is the bore dia.
Properly calibrated, they have no "bogging" problem in particular, any more than any other carb. Less than some others maybe even, given the small primaries. IMproperly calibrated (including out-of-the-box), who knows.
I ran a 6211 on a SBC 400 for many years. At various times it had a Comp 282S, XE274, and XR282HR in it. With a T-5 and 3.23 gears, it got just shy of 20 mpg on the highway, with all 3 cams.
The 6210 is still avaliable new; not sure about the 6211.
Raffman, excatly what carb do you have? (list #, approx age) I could be interested.