The core support holds a lot. I'd leave it. As to the front of the car: Cut the K-frame. Use tubing for the hood latch support, steering shaft, strut rods, fender braces. Light bumper brackets, bolts. Aluminum motor plate. Glass hood, aluminum hood pins, no hinges. Glass fenders are a lot of work for not much savings. Couldn't bring myself to run small radiator or fans either as turn around time can be short. NMCA at Bowling Green this year the time slips for the semi and final rounds were 16 minutes apart. Also couldn't give up the chrome bumpers. The biggest savings would be an aluminum block. Everything else your stuck with if you want to look stock.
Doug