Looks like you'll be needing a 90 degree drill....the PB Blaster is still helpful. Also...are your spark plugs MR? The MR plugs are marine grade stainless that wont seize in the head. On all of your exhaust manifold bolts it's good to apply antiseize compound on the threads, this will save you from revisiting the broken bolt syndrome again.... Oh, one more thing....take a ball peen hammer, smack that broken bolt once or twice good, a dead blow hammer is even better (steel head). This helps to free stuck threads too....If I think a bolt might be or is tough to remove, Ill rapp em with a hammer before even attempting to remove. Good luck.