I purchased an h23 intake manifold (plenum and runners) and as u can imagine cleaning the long runners top and bottom is extemely awkward and very hard to do. I want to soak this whole thing in some sort of cleaner as it is greasy since its been in a junkyard for quite some time. My concerns are just since its an alluminum casting its fairly porous and i dont want it to soak in any oil or be attacked and ruined by a harsh chemical. Sugesstions much appreciated

 

have it hot tanked! have them do it a couple times to try and get rid of everything! thats what i did with a couple of my parts. its not that much either. probably around 25 bucks.

 

Ditto the above ^^^ best way and a lot easier then doing it yourself. 94