I have not had a BB of mine pull less that 15" of vacuum at WOT in YEARS,if it does not its leaking somewhere. Generally all 4 vane enhanced or Star pumps(seem to be a tad better) These are all aluminum block deals and wet sumps. The Stratus pulled 19" with a dry sump and vac pump.the one iron block we did when my son first started racing the dragster as his "training wheels" was a 446" stock block that we pulled 11" at WOT. FWIW the heads up car has seen 19" as a wet sump with a moroso 4 vane on an aluminum block driven by a serpentine belt. But it is a brand X deal.