About to pick up a project car. 390FE that is apparently bored .60 over! The guy has forged pistons for the new bore size but has not yet put the block back together.

My concerns. Is .60 over safe? I hear it may run quite a bit hotter. I am looking to get 400HP and not much more out. If I could afford it I would start from the bottom up including Aluminum heads. I don't want to go crazy with it but I also don't want to drop the motor in and have to break it back down to add something later that I should do up front. So without having 5k to spend off the bat what would the best start be? Considering the already .60 over bore and forged pistons? I'd say my budget is 2k max right now. I'd like to be closer to 1K or less but i understand that is unrealistic. What is the best combo to get me to near 400HP with i already having been bored?

Thanks in advance for your comments/help.