318 crankshaft question

I have a 318 on an engine stand. This motor needs the crank changed because the harmonic balancer bolt hole is stripped. I have another crank in great shape. So question 1 is would it be acceptable to run a bottom tap in the hole and use a new ARP bolt? Secondly if I have to swap in the new crank could I just push up the pistons and change it out without removing the heads? Your advise would be greatly appreciated.
Thanks Bob