340 crank questions

I got a 360 crank turned down to 340 mains. With stock low comp 318 pistons, i figure they are out only about .015 out of the hole. Enough to bolt some heads and Felpro gaskets on. Its not balanced and has a chipped crank flange between 2 bolt holes. FedEx dropped it in transit when I sold it. I refunded the dude and FedEx picked it back up, deliver it back to me AND paid $250 that I had it insured for....not the best way to sell a crank but I got my money...and the crank back. Ill use it for a mock up on a 273 I'm toying with. 318 crank will need to be lightened big time to handle the heavier 340 rods, thats where the 340 holes come from. Youll spend more in machine and mallory metal to balance that 360 than it would cost to buy an Eagle cast 3.58 or 4.00 stroke crank. Yeah, Eagle doesnt have the greatest name, but if you dont overwork them, they are ok.