If you bore and hone a block without a torque plate, when you do torque the head in place it pulls the cylinders into an oval shape and the result is a round ring trying to seal an oval hole, and that won't work very good. You also get the same results if the main caps aren't torqued when the block is bore and honed. So to have a jam up rebuild, always bore and hone with a torque plate and make sure the main caps are torqued when all the machine work is being performed.
