200kw/auto into 185kw/man and reverse

[Jack91]

Hi all,
Just picked up another au xr8 ute, 5 speed this time (I've been missing out for so long!). Its on the wovr, and I'm sure the speedo and km reading is shonky as it has a forte speedo. But it runs fantastically.
This was supposed to replace my au2 200kw auto ute, but now I think I'd rather keep mine and swap donks and drivetrains. I've probably got 6 mo this before the 200kw dies, its leaking from every orifice, so in that time I'll build up a budget 347 and swap it over a week or so to keep me on the road. Few questions though:

How much power can the v8 t5 handle? Im assuming its got around 250k on it.

Can I just swap ecus? Obviously the 347 will get a flash tune

Are there any differences other than heads, throttle body and extractors between 2 engines?

What are the biggest pipe size extractors that will fit an au bay off the shelf (bigger than tickford ones)

End game aim is to have my worn out silver ute running the 347/5sp and the crap ute running the worn out 200kw/auto and keeping it running for a rainy day.

[Jack91]

Been reading all I can but getting conflicting info. Are there any direct replacement heads that will go on a 347 build? Preferably assembled, and not having to fly cut pistons. Car will be a manual and toy car, so I plan on getting a very large cam. Recommendations there will also be good.

Oh and also.. Bump.