arp2000 rod bolts will be plenty. It's what I use on my engine
I run DP pistons (from Greece) as it's what was recommended back in the days when I believed everything that came out of the atspeed bullshit machine. They're fine pistons, but if I chose again, I'd have wossner. To be fair to the DP pistons, I've dropped a valve on one and it's still going strong.
I really doubt that you'll be holding a continuous 6psi at 60-70mph mate unless it's uphill everywhere or you've left your handbrake on! It'll be fine for now - don't stress it, just dont cook it EVERYWHERE. But do enjoy it - keep an eye on the oil/water temps and use a bit of common sense.
Threaded Mode