Regardless if you go with pr3/p30/p73/p72 pistons, you will have to get your pistons opened 1mm on each side to fit your ls rods.
You will also need/want ARP rod bolts which cost about $30
You will want to have them & your pistons professionally installed onto your ls rods.
__________________
Authorized Dealer & Tuner for: Hondata, eCtune, Neptune, AEM, Crome, Precision Turbo, Omni Power, Walbro, Innovate & more. Dyno Tuning Services, Ecu Chipping, Chipped Ecus, Conversion Harnesses, Widebands, Fuel Injectors, Fuel Pumps, Map Sensors & more.
For more information visit http://www.Phearable.net or call 1-888-236-9831