Couple of items:
1) Stock shortblock in a MKIV Supra has supported almost 1000rwhp. Visit www.T04R.com for the details. Take a peek at Mike Carlin's beast. 980rwhp using a power-robbing TH400 trans. Many cars there making mad power on stock internals.
2) Stock IRS rearend with stock axles and a TRD limited-slip in Paul Efantis' MKIV has gone 8.255 sec @ 171 mph on DRAG RADIALS. Not too shabby for a RWD car meant for "roll-on's". What is the GTR street radial tire record? Not some lightweight either, like some stripped R32. Paul's car weighs over 3200#.
3) Visit www.WOTM.com to see the fastest 6-speed, NO nitrous, full-weight street Supra. That Getrag V160 gearbox is tougher than you may think.
4) Visit www.TitanMotorsports.com to see their 8-second 6-speed DRAG RADIAL car. They now run a 2-speed Powerglide, but ran 8's with the Getrag.
5) Somebody mentioned the stroker kits availble for the GTR. There are stroker kits available for the Supra, also, and for a LOT less money. By simply machining the stock crank, Chevy small-block V8 rods can be fitted. I am currently having this done to my new engine. Final displacement will check in at 3.3L or more.
6) At the dragstrip, we have found no GTR advantage using the AWD system. Evo's and WRX's are no trouble, either. Why? Because we race on slicks at the track. We have no traction problems. If anything, we have seen many, many broken AWD components at the track, while the RWD cars keep going. The extra AWD weight and parasitic power loss is a hindrance as well.
7) For those that think Supras are only fast from a roll (popular rumor), there are many, many videos posted on SupraForums showing the opposite. Our own Chicago-area automatic street Supras cut consistent 1.4X and 1.5X 60' times at the strip.
8) Not flaming the GTR, as it is an awesome car that deserves much respect. I hope to own one in the near future to use as a street driver and roadcourse car. But I would never sell my Supra to buy one. I will have to keep them both...
Cheers,
Dan