3L33ter

My boss at the shop I work at bought a '95 A6 with an overheated engine, it no longer runs. It's an automatic if that matters. A local was selling a '93 90 automatic as a parts car so he bought it for the engine. It had 90k miles on it.

I told him the engine codes were different so he should take the computer and stuff, but he said he'd just swap the longblock and use the A6 sensors, throttle, etc. What issues will there be with this swap? I assume the AAH motor will physically swap into the A6 with no problems. But as far as using the AAH block with all AFC electronics and stuff, will everything bolt on and will the engine run right?

I'm guessing the lower compression ratio won't be a big problem, since a high-mileage AFC and a low-mileage AAH probably have similar CR's.

My boss is giving up on it and asked if I want to buy the car + motor and do it myself.

So any tips or info would be greatly appreciated!