Yeah, I've heard so many different numbers on the weight difference between engines I don't know what to believe anymore. The lowest reputable numbers I've found hover between 40-75 lbs. But even if it is only 40, the fact that the majority of the extra weight sits in front of the axles will greatly effect handling and braking stability. Weight distribution is huge in automotive design. If it weren't, automakers wouldn't spend millions in development to swing the ratio of their new sports car from 52/48 to 50/50. And as far as the difficulty of the swap I only know one guy who has done it and he said it was a bitch. Of course, he is an idiot. His car does handle like crap, though.