[2.2 Straight six]

it depends on the way it's done. you can build a totally new chassis, you can do extensive work and add new parts to the existing chassis or you find the floorpan of a car with the desired drivetrain and you weld in parts of that floorpan into your car.

my friends work in the business of building racecars and they've done this kind of conversion before. it can be done and it is expensive. it's not, however, the cost of either three camaros or a new ferrari; depending on the way it's done.

my friend converted his FTO from front-wheel drive V6 to four-wheel drive evo-powered. it takes a lot of work including fabricating new engine and gearbox mounts. cutting the transmission tunnel out and replacing it with a one-off custom job complete with mounts for a centeral universal joint. the rear was cut out and part of an evo chassis was welded in to house the rear diff and new suspension. the total cost was about $50k if i remember corectly. including the wrecked evo for donor parts.

they needed to make a custom one-off roll cage to ensure both safety for racing and also to make sure the chassis was strong enough following the changes.

it's a lot of work and it requires a lot of time, skill and all the right exipment. so unless you have a company with all the neccesary gear and people, as well as the knowledge it's best you just go and buy something that's rear-wheel drive. might save you just a little time and money.