[Lynn Eades]

Hi Tony, Alistair, Thanks guys. When I said "full flow" I was talking about the std. system (95%) (where oil goes directly to the rear main and has the alternative option of going through the cooler (pressure is equal to both at any one time)
A bypass filter typically receives about 10% by volumne of total circulated oil.
I guess I just haven't established the reason(s) why Ford made that adapter with clearance around it, rather than having a completely sealed system of one definative flow path...... Or am I not understanding something?
I suspect only a percentage of the oil flow is supposed to (and does) go via the cooler because the hole in the adapter would be a restriction (little over 1/4") and much smaller than the main galleries in the block.
The Aussies plugged the cross drilling in the Aussie carriers (in the parts book) but used std fittings without the same sort of flow restriction.(seems better to me) This would be a real trap to someone changing the engine use, and would have caused a few "run" rear mains.