86 la 360 build help

Top end Job. A fresh valve Job will provide extra pressure on the old rings, accelerating power loss and oil consumption Have you done a dry, wet, or leakdown Compression test on the motor.??
Not exactly true.

If your bottom end is in good shape, not worn out, you’ll be OK. Do a compression test and look at your cylinder wear a second state of cylinder wall. Check the taper.