arp rod bolts let

[torquey]

Ive heard you need to counter sink the caps when fitting the bolts is this true what will happen if not done?

[Royston]

Don't know for sure, but I believe the arp bolts have a radius at the root of the shank to the head, the caps need a rebate/chamfer to stop the bolt binding on the sharp edge of the rod end cap, if it isn't done the bolt may seat on the radius, not the flat of the head

[torquey]

right its all built up now dont know what to do?

[Royston]

If the bolt radius is sat on the corner of the end cap, rather than the flat face, there will be a stress rasing condition(point contact), I would suggest you may have a real risk of the end cap chattering loose over time then letting go.........which would be a disaster

Sorry to bear bad news, would suggest removing sump, removing each cap individually to enable a rebate to be cut, inspect the bolts for damage at the shank root, if OK thoroughly clean, lube then replace/torque up.