I have dual side way mounted 4777's with four corner idle quick fuel metering blocks. I fired up my blown 496 the first time today. As it approached running temp the secondary vents had a vapor plume about three inches tall. The primary's were showing vapor but no visible plume. It was about 50 degrees in the garage. Never seen that before in many years of racing and street blown engines with Holley's. Was it just cold temps or is something causing this to happen internally? Also am using a Holley 12-454-20 mechanical pump.