Thats where we leave it up to the customer :) your call if you want to keep as much of te factory stuff as you can or not. Holley does have alot of nice swap stuff to make it easy. I guess i'm looking at it as if you have to have a T56, vs a TKX...or want a big OD automatic...you're going to sacrifice somewhere. be it fab work, more swap parts, cost, etc. I have an HDK on one car, and factory torsion bars on another. I see both sides.