I say race gas yields about 10% more power. More compression defininitly has a bigger "hit" off the bottom and top end power will suffer slightly compared to a lower compression engine.
Every configuration has its benefits and drawbacks. It is important that you work at the best balance for the intended use.
Your thinking is correct though, however race gas has other benefits, but it is possible to "make" it up with cc's.
As far as durability the cases are thicker in the crank area for this reason. Un-trenched stock cases are around 3MM thick. While we are fortunate we haven't experienced a rod failure, I am confident the cases would handle it, worst case, the alloy is repairable if it isn't.
The few on this site that have them, I am confident would attest to that, WF has seen the billet case.
Either way the design is much better than stock cases.
Buy good parts the first time, don't over-rev it, run good oil, don't let it sit for long periods of time, well taken care of, they will least YEARS.
While I haven't wrung a 701 to it's death, I have a 5 season 10MM stroker Banshee, the motor was used when I got it, I inspected the crank, put a T-Rex cylinder on it and it is still going strong. That is the best I can tell you. If you are thinking you are buying a new crank every year, I think you are overthinking it. Cranks can be rebuilt, cylinders can be bored, sleeves can be replaced.
Brian
This is something i have been thinking about, as i'd like to get off of race gas and figured a bigger CC motor can offset that. ease of getting fuel is the primary concern, especially when traveling
one question i have about the cases... would they be prone to the same problems the stock cases would have if the crank lets go? what i mean is i have seen 8mils break and rip the cases apart (blow out, crack on bottom etc)
this is one BIG concern for me, especially for the price
i was looking at 80-82 * 85mil non pv and was concerned about turning the rpms and having a crank related failure
are these cases stronger to withstand something like that?
another thought i had was going to a larger CC motor (yes initial upfront cost is costly, but with the large CC's what about being made to run on the cheap 87oct fuel, would that help extend the life of the motor and by how much (compared to premuim/race gas etc), tuning will play apart on a setup like that. I have some friends who are making decent power with their race cars on 87 oct with bigger motors
i know running the high comps you have the maintenance issue to deal with, again this was just an idea
whats been the average life span of the 10mm+ crank setups?