273 commando Build

Yes this 273 block is coming along nicely ....but..... My attention is going to be put on porting and polishing the 920 heads.. I want some horsepower to be unleashed from those 920 heads. this past engine was a beast without any real porting done . so we will see how much more hp I can make or loose. I'm staying with stock valve size.
I have read articles from guys that built 273's and ran 273-318 heads with stock valve size and ran some really good numbers. don't know how much of it was really true though..