Pulled the metal pin right off the fucker, thought i was screwed but i was able to get the injector out with some channel locks even though I mutilated the hell out of it. Now I have the plenum off the car and am installing 300 degree rails and 740cc injectors. I debated installing 555's and dremeling out the rest of the plenum like you did. But for the money I decided to go with the bigger injectors. Probably would end up being quicker to dremel all 6 spots then attempting a plenum pull for the first time. I think it took me about an hour or two to dremel one spot, but I feel like I could do it a lot quicker now.