Yes Gordon is right many have done it. You can do the engine and tranny to a full subie Manual 5 or even 6 speed with a cable shifter.
In the Vanagon model easier than the older Bay models.
Once you get the more power especially with a turbo you will need more brakes etc.
SmallCar https://smallcar.com is your first step .
SubieWorks is the California Subarugears reseller.
Count on $5K for the tranny Plus the engine and the work to swap it in. It is not cheap but then you won't do it again and you won't be peddling up hills a la Flintstone.