2006 Dodge Stratus 2.7

My 2.7 oil light was on and had a pretty good knock
in the motor. Pulled the oil pan and there's a lot of
sludge. No metal parts fell out and the piston rods
are still connected and only slight play. About to
pull the motor and go into it. This is only a temp
car and only paid $550 for it and it's in GREAT
shape. Dad and I will do the work ourselves, so is it
worth it to buy a rebuild kit and go thru the
motor?