Carter BBS Slant 170cui idle problems

First picture is threaded port for heated air 1969 and export, in 1970 that port became the the PVC valve port in usa. Yours remain the same. Second picture is it good guess.. Should be where your PVC Port is opposite side of the carburetor. The gasket should have a round hole in it with a matching hole in the intake manifold the wrong basket or no hole in manifold can be made to work by notching the sidewall that gasket