I have a kegger intake for cheap-bastard MPFI on my 65 273 (mine was $60 w/ injectors & TB). The "sucking in oil" from the lower seal is a common problem. A guy on ebay sells a thick aluminum plate to stop that gasket blow-out problem of the thin sheet-metal plate. There was also a version with a "welded triangle" to decrease the volume and/or redirect the airflow.
The long intake runners are good for mid-range torque. That was the idea of the Mopar Ram-chargers of the early 60's
and part of the reason for the slant-six intake. For better high-rpm flow, some people cut the runners short inside the keg. A guy sells plans for that on ebay. Not sure how the large volume inside the kegger helps, other than a place to store contraband.
Finally, for those ready to tell me that the bolt hole angles of my 65 heads are wrong for a kegger. I know that, have a plan, and even posted photos long ago, and no it wouldn't be easier to "just" install a whole Magnum engine and tranny.