Doing a frame off restro on a 63 & 1/2 Galaxie. It has a 352 and I was looking to drop in a 390 in it's place. While looking I was given a 429 with a auto trans for free. Here is the question will the 429 fit, and what mods need to be done? I think the trans is a c6, and the 429 is a 70/71 model year.