Quote Originally Posted by jerry clayton View Post
You can probably just look at the front and back of the heads---the air tubes attach to an point that on the other end has a plug / adapter for the bolt hole for accessories--sort of like a caterpillar thread insert----

Jerry - my recollection since I no longer have any of those vintage heads (they all went to the scrap yard)is that it was all internal, fed from the carb heat passage (but then CRS has ......now what were we saying?)