safe to do this?

[hawksnest116]

I have a 1984 GMC 1/2 ton rwd. I will be driving my 3 year old daughter and a 3 month daughter. This truck holds tons of sentimental value to me. Its a old rust bucket though. Since I will be sandblasting basically every pannel I wanted to do something..... Can you cut the frame and turn a long box into a short box? I know new brake and fuel lines would needed. I also know new exhaust would be needed as well. I wanted to find a short box bed somewhere and bolt it to the frame. Is there a way to use the same mount holes? Basically I want to restore this truck but wish it was short box.