What should I do? Refinance, HELOC or Grab from 401k

[Andrew Freed]

I am at a crossroad of what I should do to expand my portfolio moving forward. I have a 3 family that I bought back in July 2021 off market for $450K. The appraisal came back at $490K. Since then, the property has appreciated slightly so I'd say it's worth around $500K. 

I bought this property with 25% down at 4.125% 30 year, $2,155 PITI. Now I have the option of cashing out $50K via a cash out refinance at a 4.875% 40 year IO first 10 years interest only, which works out to around the same payment but interest only.

I also have the option of taking a $50K loan from my 401K which I'll pay back to myself.

Lastly, I am currently house hacking a 3 family. It's worth about $650K, I owe $520K so I can open up a 90% or 100% HELOC at a local bank at a 5 or 6% interest.

What would you do? Refinance, 401K cash out, or HELOC?