Same issue I ran into! I used my stock pistons though, so the rods had to be the culprit on mine. We decked the difference off the top of the pistons (no more than .002" variance IIRC). You're doing it right Simon, so much better to be safe than sorry!
Jason i was thinking about your old post about this
With a stock cam i would be ok.I run a comp cam as of now and its even closer anything bigger would be to risky.
Arias is doing it for free and the motor is on the stand soooooo why not