Yes, you can change the crankshaft without taking the heads off...for me, though, I would want to double check everything. With the engine out, I would want to replace all gaskets with new ones since the engine out anyway...
Take the coils/plugs off so when you go to spin the crankshaft, you aren't fighting compression.
Matthew 26:52-54 / Go Pack Go!
1987 Mustang GT Hatchback - 2V Mod Swap In The Works
1997 Lincoln Town Car, PI Intake/Cams, Sofa-On-Wheels, "Fat Tony" we call it
2001 GT Convertible - D1SC / Geared / Cammed / 440wh 400wt - TOTALED 2/2019