Re: Need some help diagnosing.
Sounds to me like you have a leaking head gasket. Have you checked the head bolts since the replacement?
All my engines get a retorque after a couple heat cycles. (Cold to full operating temp back to cold)
Don't go nuts and crank them another half turn, just check and tighten ONLY if needed.
If more is better, then too much is just enough.
If you can't afford it, build it yourself.