what is the weak link in the ls1 motor?
sounds like everything is there, but hitting 10's is still going to be a very lofty goal NA and like I said before even if you do reach the 10's it won't be for long before she goes BOOM! I would honestly take your time and build up the internals first then get more hp 
A good game plan is needed. I would make a list of exactly where I want to go with it. You don't want to buy Rods and Pistons and then have to replace it all again when you decide to stroke it.
Cost wise and through experience, find a decently priced stroker motor already assembled. Good deals are out there, I just sold a 408 for $3k that should be in the 500hp range NA and it was built for a big shot of nitrous.
If that sort of option isn't with in budget, save for it! You'll nickle and dime yourself chasing issues It sounds like you have a decent platform to play with while you save anyway 
Cost wise and through experience, find a decently priced stroker motor already assembled. Good deals are out there, I just sold a 408 for $3k that should be in the 500hp range NA and it was built for a big shot of nitrous.
If that sort of option isn't with in budget, save for it! You'll nickle and dime yourself chasing issues
It sounds like you have a decent platform to play with while you save anyway 
I have hit my 7100 rev limiter a dozen times with a stock bottom end. No issues to speak of. 118K and going strong. Although I did lose a couple of rocker bearings, and chewed up some lifters on an incorrectly ground cam lobe.
1quickirocz, your flaming is uncalled for. Do not let me see you do it any more. This is a tech forum, not a high school classroom.
In answer to your question, the cast pistons are the weakest link. They start failing above 600rwhp. You'll see ringlands breaking off a lot, especially the #7 piston. The stock oiling system and timing chains are weak as are the stock rod bolts on 2000 and older LS1s. The rods and crank are actually quite robust and can hold over 1000rwhp. Sadly, the pistons typically break before this.
In answer to your question, the cast pistons are the weakest link. They start failing above 600rwhp. You'll see ringlands breaking off a lot, especially the #7 piston. The stock oiling system and timing chains are weak as are the stock rod bolts on 2000 and older LS1s. The rods and crank are actually quite robust and can hold over 1000rwhp. Sadly, the pistons typically break before this.
I have seen the stock pistons take alot of abuse before the ringlands go. Too much boost or nitrous and some blowback will take them out though.
