If I were you I'd work that bad boy up, paint it a High impact color or what ever you like, buy it a bulge hood.
The drivetrain you have isn't the greatest of power makers and to be fair wouldn't fetch much if restored to original spec, well not in the near future anyway. I would take that 383 or wait until a 440 pops up and make one hell of a clone, an AAR would be VERY possible and those cars done properly fetch good money ($20-$35,000 US). At the end of the day it's your choice and like always the only thing stopping us in our restos/cars is money $$$, if you don't have that your going no where.
As for numbers matching you will have the last 6 or so digits of your VIN stamped on certain areas of your car.
Engine, Trans, Cowl, Radiator support, Door tag sticker and Dash.
If they all match up you have a numbers car (basically) I say basically because there are guys out there who do rat cars off although Illegal it happens, very rarely though.
A numbers car can be sometimes a bad thing, we had a guy on here who wanted to sell his numbers 340 Cuda for a clone just because you can cut corners if needs be and you can drive it without worrying as much.
Hope this helps mate. :thumbs:
