I have another Quadrajet question. I've got a model stamped "7042220", which decodes as being built in 1972. It's currently on a 1970 BB/402 engine. There's some hesitation when accelerating from idle and I will likely end up rebuilding it. (I've got Doug Roe's book...and will finish reading it before I start anything.) But, I'm wondering if there are any significant performance differences between the orginal 1970 model and the 1972 version that I have.