I ran a 406 back in the mid 80s with a cast crank and 305 rods forged 12.5 pistons ( i did not build it) and it turn 8300 every pass 10.40s in 2600lb car 5.13gears for two years. I put the spray to it a few times and after a few times of that it ran slower on motor so when i pulled it down i found three bent rods. I think if you have a good balanced engine and turn it with in reason it will hang in there. I have ran both engines and had good luck and alot of fun.
Its all in what he plains on doing, really need more info!