If eerything is the right dimension, putting an old vehicle on a modern frame is a great way to go. I have seen folks that not only used the modern frame, but the floors and the firewall also. That way you have all the later HVAC, steering and brake controls as well. If you start with a donor that is close to the same size you can really make a well riding vehicle. I don't care how good you are, you will be hard pressed to weld together frame pieces from mulitple cars or the aftermarket and come up with a better performing frame and suspension than one designed by the automakers. Not saying those can't be improved, but they are a great place to start from where everything is designed work together.

Get to measuring and see how well it will fit.

Pat