I was just given a 17056281 carburetor. A quick look reveals it's a 800 cfm unit with large air bleeds. It shows the "APT plug" on top just like a 1979 and 1980 carburetor I have. Do I understand it's a "good APT" carb and not a "less desirable" 75 and some 76 units ? Also noticed the idle air bypass holes seem quite big, around .110". Is this too big ? This is probably going to go on a very mild 250 hp or so 350. This may see future use on a 375 or so HP 400 small block. Is this a good carb to rebuild and later "resize" for bigger motor ? I have Cliff's book and read it cover to cover many times, as well as Doug Roe's book on Rochester carb.