Got rod knock piston went through the wall bought the car 3k miles ago need to engine swap wondering what engines I could put in besides just another 3.7 but the ls harness is 5k trying to find something cheaper but willing to do another stock engine friend was joking about a hemi?

 

Call me boring, but I’d recommend another low mileage 2012-13 VQ37VHR as these motors are tanks and plentiful used. Install will also be the most straight forward. It will also yield the best resale if you ever sell the car.

If you have some money burning a hole in your pocket, Stillen has their satin 50 state legal supercharger on sale now for under 7k. Stillen said that folks have installed their setup on cars with 70k miles. No issues as long as compression and leakdown checks are done to confirm condition.

 

VK56 swap it!
Could be done on a "budget"
my hairbrained idea is to find a good donor car, like a Titan, murano, or Q80. So all the harness and modules are 100% compatible with each other.

it bolts right up to a 5AT and there are bellhousing adaptors available for several different transmission.
4th VIN digit "B" means VVT
"A" is not
VVT would be better unless you want to cam it up.
You don't want the direct injection, as I don't think the tuning is figured out yet. Even with a stand alone. Not saying it can't be done, or it hasn't been done, just more work.
But the VK intake manifold out of an M56 has a dual throttle bodies. And is supposedly lower profile than the forward facing single TB intakes. Aanddual TBs would be sweet for a twin turbo setup.
I'm not sure how compatible the AWD systems would mesh, or not. But that would be awesome too.