Hydraulic horsepower is;

HP=P*Q/1714 where P is in psi and Q is in gpm (gallons per minute).

Therefore I seriously doubt the 40 hp number which leads to 970 gpm oil flow rate.

I believe the issue is more related to stress on the distributor drive leading to timing issues etc. 70 psi is getting up there though for the street IMO .............

Kitz