I have a sweep dash in my 72 chevelle,I have everything from a 71 monte.Can i just use aftermarket gages in place of the idiot lights,what about the blinkers?gas gauge plug?I'm thinking it should work.Is there a lot more to it.

For some gauges, the stock plug connections will work:
fuel gauge, 90 ohm
turn signals
high beam
brake light
speedo cable

The Gen idiot light will not work to hook up a voltage meter.

I did a conversion recently but didn't want to hack up the factory wiring loom, so I connected the new gauges to the idiot light bulb sockets. Everything has worked great for three years now. Some connections required new wires to be run:
tachometer signal
electric speedo sender
volt meter