Hello everyone, I am getting ready to start working on the 400 motor to go into my Z-28 and I have done the search on the subject of drilling the steam holes for a 400 and well, after doing some reading I am not sure what to do. I have a set Dart Pro 1 Aluminum heads that will be going on this engine. The cam will be a retro hydraulic roller unit with .563"/.574" with 1.6 Comp Cams Pro Magnum rockers. I have ROL head gaskets for the 400 that have the steam holes and Dart sent me instructions on drilling them but I unsure if I need them. I'm not sure I can do it myself and finding a machine shop here can be a challenge as well.Also, I have read here that you should do a retorque of the head bolts after running the motor through a heat cycle but that also poses a problem in that I can't get to all the head bolts with my engine in the car since these third gen don't offer much room. What's your take on this subject as well? Thanks for any info and help with this.