This is an dependant load cell test of the 244-4300 Hemi Head studs.
 
244-4300 ARP Head studs kit as supplied by ARP
 
When tested clamping force was,
35FT/LBS = 4,900 PSI
75FT/LBS = 8, 775 PSI
105 FT/LBS = 12,500 PSI
 
ARP STUD 244-4300 With Large washer as per this kit
35 FT/LBS = 6, 100PSI
75FT/LBS = 10,350 PSI
105FT/LBS = 14,114 PSI
 
Thats 1600 PSI more clamp load PER FASTENER, just by switching to the washer.
 
Another interesting note is the torque lost on a new stud, vs a seasoned stud.
When trying to make big boost we always recommend a retorque of the head studs after the first heat cycle. You will be very surprised how loose the center bolts can get after the initial heat cycle.
New Stud Loses 15-25 FT/LBS After a Heat Cycle, a seasoned Stud lost 8-12 FT/LBS of Torque after a Heat Cycle.