I am guessing 450+ a bit, basically the same engine as yours just a few different accessory's. should be faster than both being the weight difference. Now that its coming to an end, i am both excited (to drive it) and disappointed ( to see the battle with this grumpy old bastard come to an end) its been my garage life for 3 years, and even though it has put me through hell working on this early A. I will miss the battle. that being said. I will never modify or restore another early A body. You don't know how well you got it, working on a 1973 A body. you can find parts, and have room to work.