I kept having valley pans cracking and leaking oil out.I tried 3 different intakes and at least 4-5 valley pans.I could not figure out why they kept cracking.So my father looks at it the one day and says wheres your breather?I felt like such a dumb azz because i only had the pcv and a oil cap on the other cover.I was surprized the vaccumm was strong enough to crack it.