Impco 200 wahat is this for?

[It'sNotWorthComplaining!]

I have an impco 200 convertor and there is this protruding casting on the inlet throat. there is a solid nut on the outside, what is this for?
http://img69.imageshack.us/img69/6104/s6300106j.jpg

[bee utey]

I have an impco 200 convertor and there is this protruding casting on the inlet throat. there is a solid nut on the outside, what is this for?



Breather port for PCV equipped engines. You screw a hose barb in the outside and connect the fresh air hose to it instead of the throttle body. Not required on a D1/RRC engine unless you believe some other forumites. :p