Hi Neil,
I used to turn down the original filter body (so it's probably less than 2" total) it was just an oil way. Then use a Mocal remote oil kit - they did a 5/8" oil cooler kit that used the normal oil coolers oil transfer take off - and included a remote filter head in the feed to the oil cooler. Mocal TOP7b (I'm pretty sure the Dolly/TR7 TOP7 adaptor has 1/2" outlets and TOP7b Stag has 5/8" - I used 5/8").
Turn down the original oil filter housing just so you can bolt it onto the block - you'll notice the oil flows out of the pump through the original oil filter and then through the oil transfer adaptor up into the main oil gallery above the mains - do the same as you would with a head and clean up these areas for good oil flow.
Hans posted some pics a while back about the oil flow
http://sprint.smugmug.com/gallery/45234 ... 3518_Dtso4
As you say rocking the engine over slightly gives a bit more room for the manifold - modify the nearside inner wing to give a bit more room as well (you'll need it if you move the engine slightly back - rather than sitting straight onto the subframe the engine can be mounted the width of the engine mounts further back like some Ken's done).
Cheers,
Ben