in stock format 240 vs 220 hp. but the gen3 is more responsive to light modding. 
 
the gen3 ecu, fueling and turbo can handle up to about 17.5 psi without too much trouble, where as the gen2 can only really manage 14psi, and the turbo runs out of puff after 5500rpm.

Would it even be worth using interchangeable parts from a gen 3?

...As opposed to doing an engine conversion with a gen 3.

What's the name of that thread?

IMO its better to just go aftermarket.
 
Oil filter location is a easy thing to pick. Gen2 is near the turbo and Gen3 is off the front of the sump.
 
 

Gen two with ct20 and 17psi is a fast car. Just ask my mate in his bmw m3!
And if gen3 is quicker, than its QUICK 😄

Gen 3 is logically a bit more powerful with a few better components, but once they're both mildly modified the differences don't matter as much. Its a nicer base to start from, but if you've got a gen 2 don't bother looking for parts from a gen 3, just go aftermarket and you'll be even better off.
The biggest drawback is the turbo, the CT26 definitely becomes a restriction. If you're lucky someone else will have already swapped on a CT20B :D
(FYI the CT20B just says 'Toyota' on the inlet)

yeh, gen3 really wins mostly in stock format. if you already have one it's cheaper to get more power out from compared to a gen2, as you have to upgrade the ecu and turbo to get to the same limit the gen3 can on stock components.
 
then you also running the risk of blowing the stock HG as it's composite not MLS like gen3.
 
but it's not worth spending the money to convert to gen3, money better spent on uprgrading what you have.

Well I've already got an EMS 8860 ecu wired up, so with a better turbo, and maybe some aftermarket cams It should have enough power to satisfy me haha, not that it doesn't already.

So I take it the CT20 turbo is what a gen 3 has stock?

^yep gen3 has the 'CT20b' stock...

Anyone have one spare they want to sell?