I have a 383 a-body and they are a real pain in the azz!! Headers are Very expensive for one. They are very front-end heavy and will tend to PUSH in the corners. Driveshaft has to be shortened. trans need to be BUILT for the torque. Considering power to weight ratio it may be in your best interests to go smallblock. Lotsa power from a smallblock and weight is not an issue. The 360's are everywhere and cheap. The 383 is going to be a problem with pistons too!! I know, I just scraped a cracked 383 that was my build engine. No off the shelf pistons available except stroker pieces and a minimum of $900.00 for a good set of pistons. I just passed on the idea of the stroker from 440 source. They are on sale for $1887.00 complete with forged crank-rods-pistons-rings and inserts. All you need is a 383-400 block and can achieve 500+cubic inches.
I now am using the 400 block. I will be building my own headers since I am using a S480 76mm Turbo. I will be posting pictures of the build shortly in the Forced Induction forum.
O'yeah, WELCOME to FABO!!
Good luck on you endeavor!!