High egts at idle

I've got a fuel injected small block on M5, seeing some high EGTs at idle trying to get it figured out. Fuel is low 4's AFR and timing I have tried 25/30/35/40/45 degrees. 10 degree heads, 10.5:1 AFR, Promag 44, -10 plugs gapped at .018. At idle seems like EGTs are a solid 825-875. Down track EGTs are inline, just seems hot at idle and pics up temp quick. Motor is solid filled, heads are dry decked. BS3 with the NTK sensor