The stock rear diff is a WEAK link! i have seen several of them die on 350 hp cars with an aggressive clutch ( often taking the gearbox with it to the afterlife!)
So this is the first thing you need to change.
Next thing you MIGHT brake is the gearbox itself ( syncros, or forks. ) But this is not really from the power, it`S more from abuse.. you do need to use the clutch when changin gears with these gearboxes.
My tip would be to get a st205 gearbox, since they do have alot better syncros and forks.
I have also seen a few center diffs not working as they should, due to they starting to get old.. you could "weld" it as me and another guy here on the forum did, but you have to be carefull when parking in tight spaces..( the other guy here on the forum killed the center diff when parking?, but mine have been ok for about a year ( with alot of hp..)
Other than that, you should be safe for whatever power you can trow at it... i have yet to see a gearbox, driveshaft or axels get broken due to hp\tq. So this isn`t really something you have to worry about. Just remember to take up the slack before you launch it.. ( like you have to do in every other 4wd car.. )
Thanks for the input. Is the ST205 rear diff much stronger? My plan as far as the trans goes....I have free access to a 2wd dyno at my shop so I was going to use the ST185 trans in 2wd mode to get the tune close and get any issues figured out with no fear of breaking it. Once I get any issues figured out, swap it out for a ST205 trans. It's good to hear the axles and driveshafts hold up well. They were my big concern.
PS: the guy from greece also have a low 10 sec car running a stock 205 gearbox..