joe gibbs xp4 15/50 non synthetic(breakin). like i said last 2 builds had .002 on rods and mains with full groove and using 20/50 amsoil, no issues. i had 100# oil pressure when first fired up, 75 when it got warm and 55 when it let go.
Your oil pressure was a little high, especially at idle, I wonder if you had a restriction somewhere?
Also rule of thumb for oil pressure is 10psi per 1000 rpm , 55psi at 6000 is a little low especially with that thick oil .... but that could have been the bearing going away at that point ?
