Impressive for sure, IF this is a bracket deal, why stress it snymore than it has to, it makes great power at 6600 ! why go higher just looking for 2-3 HP??

Also, what amount of oil in the sump? it loses a little oil psi at the higher rpms so maybe it has a qt too much in it?? Just something to try, and maybe find a little more power. BUT wow 895? at 6600 thats a nice bracket engine