Why not add a filtered circuit on the side of pan. A simple DC powered pump that sucks from pan and pushes thru a filter back into the pan?
1) Lack of real estate (pretty tight quarters all the way around).
2) Looks. The pump and modern spin-on filter don't really belong under the hood of an early 50's era hot rod. Not to mention the hydraulic lines are kinda ugly (at least in my eyes).
3) $$ I looked at electric dry-sump pumps and peripherals for turbo oiling (over coffee this morning). One can buy a lot of oil changes for the cost . . .
