Quick question for those that's done it - the oil tank holds 9-11 litres of oil but can I get away with adding 5 litres to the tank in order to dial in carbs and generally rev up the engine? Can't see that I'll go over 4000rpm and there are certainly no corners involved. I want to get everything thing right and check for leaks etc before fitting the engine back into the car.
Once finished I'll be dumping the oil + filter

Hi James,
happy to hear news about your project.
For testing my engine i used a self build oiltank, made from an 10l fuel canister ( don´t know the right expression in english, sorry).
I added approx. 5-7 l cheap 15-W40 Oil. I think that cheap stuff can´t harm the engine if it runs only on idle with light revs. With this homemadde tank i was able to see the oillevel everytime. With the oem Tank you can´t see this because it´1 completely closed. My advice: dont´t try to save some bucks and shot the engine. It isn´t worth the hassle.

Thanks Mike -I'm sooo far behind on this, but had a bit of rust repair to complete. You're dead right not worth junking the engine for 6quids worth of oil

My benchtest is similar to yours -a bit Heath Robinson