AMS has just announced their big-bore 4.4L GT-R crate engine. This is based on the technology of their previous 4.0L crate engine and adding a billet stroker crank. The increased bore, stroke and compression ratio gives the engine more low end torque which helps reduce the turbo lag. Check out the dyno sheet below.
I have no idea how much power you could put through this. Their 4.0L crate engine was able to handle 1,500 horsepower. So if you are looking for one of the craziest engine platforms out right now and are willing to break the bank, this might be your next purchase.