Welcome Aboard "KB9GIB"! Nice '79 Aspen R/T you got there. Looks like an original 318 car and yes, the A57 confirms the package. If you have all four of those original Honeycomb-like Factory Wheels, hang on to them. They are hard to find and you might someday want to put them back on there. It would be cool to make that a real great Handling/Autocross car and keep it looking somewhat original...The Stealthy Sleeper theme! Lots of suspension help from the company "Firm Feel" and "Magnum Force" can be had. I had a '79 Volare Road Runner with an original E58 360 in it, back in the early 90s when I was but a young lad... Ended up rebuilding the 360 and then sold it to a guy in Upstate New York who turned it into a dragstrip car and essentially ruined a real Volare Road Runner... It was his car to do what he pleased with it and it did run well down the track, but it's a shame he had to use That particular car for it! I am reuniting with an F-body I used to own some fifteen years ago this coming spring, so seeing your acquisition is keeping me at bay until mine arrives!
That being said, Congrats on picking up a rare one and Good Luck in making it to your vision!
Cheers, SooperKoop