my honda accord is about 3300 lbs. i doubt your suv is 3700.
600HP out of a supra engine is not going to be very reliable. and i think its very highly probable you'd lose your front wheels for power, making it harder to lay down the power.
go for it... you've certainly got some balls if your really considering it. but i think you'll be dissapointed unless you throw alot of money at it. like twin turbo's and the works.
good luck.
supra TT