Originally Posted by soapy_junk
with regards to the intake vents... it seems the accepted practice here is the 3" holes with the pipe nipples.. 2 capped and 1 ball valve..
I hope you meant 3/4" vents. Instead of having three separate vent openings a single 1.5" ball valve should also do the trick. The 1.5" ID vent gives you more intake volume, somewhere close to having four separate smaller vents. I think this approach gives you more latitude from a single vent.