We had another successful run this past weekend, we picked up four intake manifolds from the 3.5 V6 Dodge Charger / Chrysler 300's. We verified the flaps moved freely before pulling them. My question is how deep do we need to clean them out? Is it just a matter of cleaning the outside and making it look good or should we go ahead and try and clean out the carbon build up inside? Is it worth the extra time / energy / cleaning supply cost? I see most are sold uncleaned? Whats the best course of action here and how would this apply to other engine parts we may be pulling?