Help please as i'm pulling what's left of my hair out!!! :x

My FRST has been leaking oil for months now!!

The story goes....................................

After putting my enigine back in over 6 months ago (after a full rebuild) it's done nothing but leak oil. The problem is though that i can't pinpoint where!! If i drive the car around town doing 30-40mph there's not a drop of oil? But as soon as you put your foot down or go on the motorway doing 70+mph oil p*sses out everywhere!

I steamed all the oil off the engine (Cambelt side) as it was everywhere and could not source the leak. Took it out for another spin and pull over to see if i could catch the leak or where it was coming from. But there was oil everywhere again.

It seemed both times that the oil was on the bottom half of the engine, my thought might be that the crankshaft pulley seal?(i had replaced it when the engine was out but i thought i may have ripped it or whatever?).

No joy! after replacing it it still leaked like a trooper. So off came the head to change the head gasket even though the one on it was 6 months old.

No joy! I've check eveywhere for torn or damaged pipe/hoses replaced ones that may have seemed dodgy. still no luck!

After leaving it for a week or so to try and think of something that it might be, i came to find that the oil pressure wasn't up to what it should be? Which baffled me a little bit as the pressures not up but it's forcing it out of somewhere when it's driving?

So took the oil pump off and found it was on it's way, so i replaced it. And took it out for a spin last night and it's still throwing it out!!!!!!!! :x :x

Coming to the end of my rope now! Just wondered if anyone had come across this problem before?????