4l60e transplants?

I'm wanting to retain the electronics, I will be using the A41 conversion kit from keisler hopefully, but tunnel surgery is required for the early a's, although they do have a perfect fit kit for later a's.. how much bigger is the tunnel for 67 up cars? Is that good news for me? maybe just a tad bit of massaging? I won't be using torsion bars so the x-member can be cut out/modified.. but do you think that will weaken the unibody alot? I will be putting in frame connectors and torque boxes as well. I'm really just trying to figure out how much surgery this is going to require. :sign7: Does anyone think transplanting a 67 up tunnel into my car is possible? :sign7: Could use a later console then without modifications possibly? Any thoughts?

Thanks,
Ryan