I measured the ARP 2000 rod bolt stretch on a set of Scat 7.100 long rods with the Mopar big end today, I had to call Scat to try and get their recommended stretch and torque recommendations on thses bolt( 1.800 under head bolt length, 7/16 bolt diameter. No luck so i called the machine shop that I had pin fit these rods to the wrist pins in the pistons I'm going to use and had them check the rods for roundness and fit on the I.D for the rod bearings, they didn't return the instructions that came with those rods so I called then 2nd. They had to look and called me back and siad they didn't find the original sheet but looked on line at Scat site and came up with 70 Ft. lbs. with ARP lube and no longer than .0060 stretch.
My message is I saw around .0032 rod bolt length variances on these rod bolts with no load, I torque them all to70 Ft. Lbs. and that stretched them between .0041 up to .0053
I'm thinking I will loosen several of them tomorrow and retorque them up to 75 Ft. lbs. and see if that helps getting them closer to .0057 up to .0060