Has anyone had any experience with an aftermarket oil reservoir? I am looking at some on e-bay for 39.99 plus shipping. Is there still pressure on the system?(I mean is there a cap that has a one way check in it or something?) I considered making my own system but was unsure about using a vented cap or not. How hard would it be to install a factory type one on my boat? Mercruiser 140 hp alpha one gen 1. I currently have it torn down for bellows replacement.<br /><br />Thanks <br /><br />DougV>