16yrs old, first car advise?!

Sell the 383 stuff.
Then, get some 3.91s, an LSD, a 2800TC, a 4bbl, a freeflowing exhaust,and a rev-limiter or some 5500rpm valve springs. Then go have some fun; Zero to 40 mph at lightspeed,lol.
Some of my favorite memories are attached to such a combo.