QUOTE:
"keeping the rest original" 
Well... except for the cowl hood and mini tubs... Yes, the body will look the same. I'm going to put a new dash in it so I can use white-faced gauges but the carpet, seats, console... will be stock.
QUOTE:
"why are ya putting a 383?"
One word... TORQUE!!! A 383 is actually a 350 w/ a 400 crank. Of course you deck the block, ... It's about as RAT as you get, especially w/ a blower on it! 
A friend of mine has a 69 w/ a NAZTY 454 that produces so much torque, it actually cracked the NEW paint on the quater, just under the rear window!
Another friend has a 69 w/ a Chevy ZZ502 crate motor (502hp). That thing is INSANE!
Bob's 69 ZZ502 
And one more friend has a 67 Pro-Street Camaro w/ a 427 pushin' over 685hp! Now THAT is a fun car to drive on the street! Not very far though! 
Garry's 67 Pro-Street