First of all, I understand why you would want to make a drift gt. that is exactly what I am doing.
But here is the reality: I have spent over a year building my car, and I am only about 3/4 finished.
Read this whole thing.
http://www.opelgt.com/forums/engine-swap-forum/25560-94-13b-twin-turbo-into-71-gt.html
I am doing ALL of the work myself, so there are no labor charges involved. so far I have spent well over 20K. 20K just in parts, that doesnt include any of the special tools I have had to buy to do this kind of work. I figure I still have 10k to go.
And there is just about nothing you can buy that just "bolts up" to an opel gt, I have had to make or modify everything for this car. If you want a drift car, buy a 240. The S14 chassis is really set up for, and supported by the drift aftermarket. The opel gt is supported by almost no high performance aftermarket. these cars are just restored by guys and (for the most part) driven gingerly on the weekends. there are a few guys that are doing serious racing with these cars, but they are spending serious money on them, and doing serious modification/fabrication work, and have serious years of racing experience, and my hat is off to them.
read Rally Bobs 1.9 tips and tricks. get your cars original powerplant up to around 150 wheel HP and see if that doesnt make you crap your pants.
overall, the opel gt is not set up for drifting. the suspension sucks, transverse leaf spring is in a flimsy front cross member, 0 camber, 0 caster, no adjustability, very limited steering angle, the car sits about 4" too high stock, solid rear axle that only handles 150hp, open differential, the chassis will torque in half under any heavy launch conditions, if you slap a wall you cant just zip tie your bumper back on, you will have to do serious metal work, and the list goes on and on. If you solve all of the issues, it will be a great drift car, but there are lots of issues to solve.
When my car is finished, with this engine on 15 lbs of boost, it will be making something in the low 400's, that is a 5 to 1 weight to power ratio (eventually I will get a street ported boost built high rpm engine on 25 lbs making mid 500 hp, revving to 11000 rpm:ugh

. Anything over about 250 hp in these cars (set up properly to hold and plant that power) is useless and dangerous. a 250 hp 240sx is a legit drift car, and it has almost another 1/2 ton on a gt.
My gt is just going to look kinda like an Opel gt when it is done. it will just be the shell with a completely custom modernized drivetrain. the only thing I am keeping original is the lighter on the dash.
If you still think you are up for this, and you arent going to just start cutting on, and then discard an Opel, be prepared to spend at least 30k for someone to do even the most basic drift build setup. (roll cage, frame re-enforcement, engine swap, suspension fabrication)
If you want something that looks cool, that you might be able to toss around a corner every now and then, that you might finish in a timeframe that still holds your attention span, then keep it stock and beef it up.
And FWD drifting? Guys, seriously? I know that drifting is a new form of racing and not everyone takes it seriously, but can we please get our facts straight? Drifting is not just yanking the e-brake and powersliding a corner. Legit drift racing is very technical, and takes alot more skill than hollywood lets on to... The only drivers that are more competent in more racing fields are the rally racers. If you can have absolute control over your car when it is 70 degrees to the curb going through a sweeper at 65 MPH, you can pretty much have control over it under any conditions.
Mike Lambiase