Dale, Bob Homewood raced an XU1 during the '70s and would probably be of help with this. He usually isn't too far away.
Dale, Bob Homewood raced an XU1 during the '70s and would probably be of help with this. He usually isn't too far away.
For all the early long distance production races and the GTX series we had to run the factory cylinder heads with the correct factory part numberrs and they were all supposed to be exactly as the GM bulletins said with no modications unless the bulletin allowed it I did have a copy of all those old bulletins but somedody borrowed and has not returned it,however there must br other copies out there I can't answer the question as to what anyone used later in say the modified 0-4200 class etc ,but that is a different matter