I recall putting an aluminum fitting into an aluminum manifold and it seized up tight - like forever! So, maybe I did something wrong or what is the best/better pipe plug material for aluminum intake manifolds? I have brass and steel and am afraid of aluminum now.
I tried Google for this and - well - some say aluminum with anti-seize is fine and some say brass because it is close in galvanic properties. Or stainless steel (harder to find).