This is has been a subject of much debate and yes the main culprit has been the rods, but as long as you are in there, which is very expesnisive especially as you <must> have an extremely competent shop to meet those tolerances, you might as well do pistons and rings anyway.
Fact: All or Nearly all forced induction 350Z's w/ catastrophic failures have been Twin Turbo'edFact: Usually those failures occured within a month or less of installationFact: often those failures occured on engines running only "stock" boost or only slightly more.But also..
Fact: Hundeds of twin Turbo Kits have been sold and installed, if every one of them blew, we should have heard of more failures than we have.Fact: Twin Turbo Kits generally offer better performance than the SuperCharger Solutions (which arent trouble free either).
I have been facing this same dilemma , i can afford a twin Turbo kit comfortably, but an internals build-up would break the bank.
I dont want to wait so I decided to run a supercharger as discussed in this thread:
http://nicoclub.com/zerothread?id=99454
However keep in mind that great performance w/o forced induction is possible as discussed here:
http://nicoclub.com/zerothread?id=92664
Also one thing I noticed when reading about failures the possibility of an overboost condtions having occured, can NOT be excluded, also nearly all those failures, have been on the low quality California/Arizona gas formulation.
Then there is this issue, which is likelly an additional culprit independent of gas or tune:
http://nicoclub.com/zerothread?id=99972
In summary while it seems you could probably get away for months on a stock internals, with high quality gas, a good tune and a aftermarket CAS wire.. its still very risky...and if the car is a daily driver I wouldnt do it..
I think a SuperCharger is a safer solution. This is why:
-Overboost condition is impossible, due to being belt driven-Few SuperCharger failures have occured and the ones that have, usually lacked a timing solution such as a J&S Safeguard.
These guys currently run a sale on 350Z ATI ProChargers, much less thanthe price listed on their website:
http://www.injectedperformance...id=33
This vendor can get a good price on the HKS Rotrax kit a highly regarded kit (albeit not cheap from any vendor)
http://shadowdragonracing.com/wst_page2.html
Even on SuperCharger an internals build-up is not a bad idea, but it has been shown, that if your fuel and timing tune is good and you keep with the stock pulleys, problems are very rare.
Fred..