With all due respect fellas these motors that you all are talking about are either way too expensive or are unattainable.. Nice thought though guys but I think you are 5-8 years and still thousands of dollars away from making it happen in my humble opinion....
I am currently working on an LS1 and mated GM tranny swap into my 1992 SC400...With the Ls1 and Ls2 motors you can achieve 400hp N/A with just a few simple mods.. This Gm tranny, ECU, and LS1 motor can be purchased for around $2000-$3000 for everything running... When swapping into an SC400 you need to weld and make some custom fit motor and tranny mounts, hook up with a driveshaft shop and make one side toyota and other GM and that is about it...Drop it all in, integrate the ignition, throttle cable and cluster in accordance with the GM ECU...Wiring diagrams of both motors and cars are needed. Then you are looking at one very very fast and somewhat reliable SC400. Then if you ever get a wild hair and want to boost the LS1 motor then sky is the limit...Those GM auto mated trannies out of the GTO's and Camaro's can hold good decent power too... I left out that the LS1 headers are a hard fit in the engine bay of the Sc400's, custom made flat headers will need to be made or part of the SC400 chassis will need to be cut out ....Not a big deal, but other then that it all fits in... The shifter on the GM auto tranny is positioned 6 inches to far back but a little custom work and it is doable as well...
There is not a better swap bang for the buck then that guys...The problem is that most Toyota and Lexus owners curse GM products and won't even entertain that idea... However, If you can get past that hang up then you will be good to go as I am...