[DanEC]

Back when I had my engine built (about 2010) Keith Craft was charging about $500 more for a 428 core vs a 390 core - not a whole lot of difference but the market may have evolved since then. If you want maximium cu in with a stroker crank the 428 will go a bit bigger due to it's larger bore to start with. In the 445 cu in range you can work with a 390 and 4.25 stroke or a 428 with a 4.125 stroke. If you save the $500 on the 428 block and put it in a set of aluminum heads on the 390 instead - you will no doubt be HP ahead in the end - can go with a bit more compression and better breathing. Lots of combinations to choose from.