I'm by no means an expert on any type of engine...however, when it comes to talking about numbers matching and stuff like that...

First you have to decide if you want to hotrod it or if you just want a good solid truck.

Hotrod = pull that 283 out, wrap it in plastic and tuck it away in a corner. Then drop a 350 or a 383 in there and go tear up the street.

Solid Truck = pull that 283 out, rebuild it. Bore it just enough to make the cylinders clean again. By a good piston, use the stock rod. Take your heads to a machine shop and have them cleaned and rebuilt. Use just a pinch hotter of cam. Rethink your whole exhaust system. (maybe some headers)

Either way you should convert to HEI, redo the exhaust, and have the whole thing cleaned up.

Now, the numbers that the 283 puts out after the head work, exhaust work, rebuild, cam change, ect. won't be much different from stock. But you'll be able to notice a big change. Especially if it has been a long while since that motor has been rebuilt. IF YOU DECIDE TO CHANGE ANYTHING ON THE MOTOR TO AFTER MARKET, WRAP THE ORIGINAL PART IN PLASTIC. I cannot stress this enough. The original parts aren't replaceable.