Thanks everyone, just had another look at block casting numbers and there are only 6 digits and is the same as my old block it may be an Australian thing but my original engine and truck was built in USA .
They other numbers tell me that the engine is a August 1943 block so that is good,
another small thing I found is that that oil line t hat passes through the water jacket on my original block between piston 4/5, the 43 block has the line through the sump/ crank shaft. I think it is a better idea ????
Cheers Justin
