Ls3 swap or rebuild the n54

Recently checked my compression and I’m low at 120 psi in all cylinders and it’s supposed to be 170-180 so I’m on the verge of either building a Ls3 to slap in or rebuild the n54 from bare block. But I don’t wanna do something ima regret like buying this mf in the first place. So ls3 or n54 I was think 2jz to but I seriously don’t know 😩😂