the standard ones are more or less the same but these are HIGH TENSILE 4340 FORGED STEEL
HARDNESS OF HRC33-38
DOWELED CAP FOR PRECISION ALIGNMENT
X-RAY & SONIC TESTED, QUENCHING AND HEAT TREATED,SHOT PEENED, 100% MAGNAFLUXED
SILICON BRONZE BUSHINGS FOR FLOATING PISTON,WRIST PINS ,ARP 2000 CAP SCREW BOLTS
(sorry about the caps i just cut and paste from the add)
when you work it out you are not paying that much more if you needed to buy new rods and arp bolts plus these arp bolts are larger than a-series arp bolts
spool rods