Definitely go with the QR25DE. It's newer and there's no substitute for cubic centimeters.

I suppose that inherent in my laziness for desiring cruise control and an auto is also shown in not wanting to spend many hours trailblazing the conversion and many more dollars on sourcing a suitable motor etc. (Although I am almost prepared to attempt a silvia dash). It is summed up in a advert on TV here in Oz "I just want milk that tastes good and is good for me" (and only 2% fat).

Admittedly a 2.5Ltr in my little ute would look and sound nice but as far as i can see the only widely sourceable donour here is an x-trail (not really an affordable option) - yes i want my cake and eat it too.

The other thing that does not quiet help is the wikepedia on the engine itself http://en.wikipedia.org/wiki/Nissan_QR_engine#QR25DE under the title 'Manufacturing, design, and assembly flaws'

I do appreciate the suggestion, the more research i do the more prepared i will be when i do make the decision.

cant imagine it would be all that hard to have AC and cruise on the CA or SR. the interior part of teh AC might be a little hard, and fitting the AC cooler and intercooler and radiator in the front of the car. but space issues will probably be the most of your problems as most of the wiring would be straight forward enough with a wiring diagram and if you are using the silvia box and dash most of the wiring will stay
will just need a whole heap of neatening up and what not to get it all to fit and look half decent
as you would probably just get rid of the 1200 loom all together and just fun the whole siliva front half of car loom instead. then it would just be a matter of going through and getting rid of what you dont need

ok i think im gona go with the CA swap, will be pulling it down as soon as i get it anyway. that spool stroker kit looks pretty good, would anyone recommend it at all? i am a really big fan of I-rods. thanks a heap to everyone for the feedback, its all been taken in.

spool stroker kit is pretty expensive isnt it, and with a turbo that isnt too lagy you probably wont need the low end torque that the extra capacity will give you as much

i think i read the spool kit being something like 2800 bucks, so are you recommending them or not? in the way of turbos, do the t28s spool up quickly? i was having a look at one on the net today and the exhaust housimg looks sorta smallish?