if I am at 2 life and am attacked with a 5/5 with trample, and I block with a Kjeldoran Gargoyle, do I survive?
if I am at 2 life and am attacked with a 5/5 with trample, and I block with a Kjeldoran Gargoyle, do I survive?
Yes. Since your Kjeldoran Gargoyle deals its combat damage first, its triggered ability will go on the stack and resolve before the 5/5 with trample assigns its damage. So, you would go up to 5 life, and then down to 3 (since the trampler must assign 3 damage to the Gargoyle, only 2 of it goes through to you).
Incidentally, the Gargoyle's lifegain isn't quite the same as lifelink. Lifelink is a static ability now, meaning it happens immediately after combat damage is assigned. If you were blocking with a creature that had lifelink, it wouldn't even need first strike for you to survive -- you would simultaneously lose and gain life, keeping you above 0.