An LD28 crank is not really an option for you Tom. It would mean you would have to get different rods and different pistons. Also they are hard to get, and anyone in Aus that is selling one, wants an arm and a leg for it. If you have friends or rellies in NZ, then they are pretty easy to find and relatively cheap too. If you go the LD28 crank route, I think you would be building a 3.1 litre stroker engine, and should have a read of these before deciding to: http://www.geocities.com/inlinestroker/ http://zhome.com/rnt/3.1Cobb/3.1engine.htm http://zhome.com/rnt/3.1HanveyProject.htm If you go the standard route, and go one size overbore with appropriate pistons, if you still have the option to go the next size later, if you need to. If you go the max overbore straight away, and ever need a re-bore, you would be looking for a new block.