Can I refi my private loan?

[Tim Klotz]

I bout my first property in July, using private money to aquire, and rehab.
I have comps in the high 60's to low 70's, i will have no more than 52000
total in it, i would like a cash out refi when the rehab is complete for 55000 (approx 78% LTV) to pay off the private investor, and cash out. my credit is about 600-620. How difficult will it be to refi w/ my credit and 78%LTV?