After reading all the responses to my Original question,I called the manufacture of T&D rockers. Unfortunately, they would not commit to an answer weather the pushrods needed to be changed without seeing the install. Very good answer on their part. However, has anyone who's reading this thread actually had T&D rockers installed on stock 97 heads. If so, please give me your imput. Did you HAVE to change the pushrods for proper fit and performance? Thanks for all of your replies. Tim