Most fastener manufactures will allow for a 10% over torque, What ARP says I can not speak on.

But how old and accurate is the torque wrench? Has it been dropped? If a clicker style, when was the last time it was calabrated? Has it always been retuned to the lowest setting?

These are the things to keep in mind when torquing bolts.

If you use a 1/2 torque wrench then use a reducer to fit the 3/8 socket, or you use a extention, you will loose a bit of toque due to flex and/or twist.

I used a 1/2" digital snap-on torque wrench last time I did it. But I did use an adapter and short extension. Final torque was like 90-92

+1 to SVO's food for thought. A tech is only as accurate as his tools will allow.