I just got a couple 4 inch cranks, one cast and one forged, I am going to use the forged one in my 340 in my car, it has a destiney

I was thinking about useing the cast crank in a 318 block for my truck along with a set of 5.7 hemi rods and pistons. If my calculations are correct it will be a low compression deal mabey 8.5 to 1 I can bore my block .010 over (it has no ridge and hone marks all the way up )it is a magnum block and I have a good set of magnum heads. All I would need to do is pay for boreing or honeing and balancing, is all this possible? With the pistons and crank in a 340 block the top of the piston is a few thou below deck.