it depends on your hp goals and your budget. 150k is a lot.. and kinda chancy if going turbo.. which imo is the only thing to do with D's. NA on a D is just waaaay to expensive. i'd suggest picking up a low mileage d16y8 with tranny too. and put together a turbo for that. your turbo will pretty much bolt all up to your b7 or whatever it is that u have, since its also a D-series. but i just don't know how beaten on it is. you could do a compression check on it and that would give u a good measure of how stable it is in its current condition.

goodluck bro.

-Luke