Weight is definately an issue. With the big block under the hood and a driver in the seat I'm guessing close to 4,000#'s. I have not had it on a scale. I agree 3" exhaust would be best, but I've got a 2 1/2" S/S system with Borla Turbos and mandrell bent tubing under it now that I was going to reuse when it swap out the small block for the big block. How much HP do you think I'll give up w/ the 2 1/2" system. Thanks for your input!