a thought in a different direction...
An "over-bored" block can and will have overheating issues. The cylinder walls don't have enough meat to carry away the heat. Any sonic testing done prior to assembly?
Pusher fans are worth squat. They're more for show than anything else. People who brag on them tend the be justifying their own financial expenditure.
Things to look for:
1) Good shrouds, radiator inlet and outlet (air recirc at idle is a problem)
2) no under-drive pullies. Under-drive your water pump and you'll have problems.
3) Good puller fan. El and myself use the taurus fan. IMHO, there are none better.
4) don't use too much
antifreeze in the mix, water wetter seems to help a bit too.
to name a few...