Incorrect baseplate causing rich idle ??

[CDNSS]

Working on a 215  QJet   69 396 Chevelle carb ......... cant get any response from idle mix screws  and idling rich ....... I now see the base plate has 2 screws holding it to main body( I thought should be 3 )  and no idle air bypass hole drilled ........... could this be my problem with idle mixture .......what can I do ??  Drill holes in throttle blades

[qjetsrule]

I think the 3 screw baseplate started later, '77 on up. You may be idling off the transfer/main circuit. Turn the carb upside down and compare with picture. If the transfer slot is too exposed you may need new idle tubes. Bypass air may be required if you are running a large cam. Cliff can hook you up with the right rebuild kit. Good luck.