I have an 02 em2 with a k 20a3 swap, but I just spun a rod bearing. I had planned to replace it with a k24/k20 build but a friend has offered me his stock z3 internals as he has upgraded to crower. I was wondering which z3 internals I could actually use as he has everything from crank to cams and if the result would be better as far as cash spent to power gained ratio vs the k24/k20 build.