I put the rods/pistons in my 225 today. These are the rods I used ARP 142-6001 bolts in. The stock rod bolts are torqued to 45lbs, and ARP bolt specs are .0055-.006" stretch, or 50lbs if you don't have stretch gauge.
Like I do with every engine, I torqued the bolts to the specified amount (50lbs) using my Snap-On torque wrench and ARP assembly lube on the threads*. As with every engine, there is not enough stretch. I checked each bolt and got .0035 -.004" max.
So....I increased the torque. It took 70lbs. to finally hit .0055". This is something I've seen on pretty much every engine I've assembled, it's not a unique occurrence. I'd guess ARP will tell you the clamping strength of the bolt is way under spec at .0035" stretch. Some food for thought if you are using a torque wrench alone.
*I fully cover both threads AND underhead of the nut with assembly lube. I've found that if you leave the underhead dry, it wastes a good bit of the torque effort. I'd guess a dry underhead on this application would give you .003" or less stretch at 50lbs..
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When I did the torque-angle method for my K1 rods and ARP bolts, I went a bit past the angle they recommend (about 5 deg more). K1 specified using torque-angle or stretch methods, and that torque alone was not acceptable.