$4,000-$5,000 is enough to get you a nice shortblock.
My DSS 408 Windsor shortblock minus cam was around $4,200 with custom Venolia pistons, 4340 forged crank, Hbeam rods, MSS, Windage Tray.
A $5,000 budget is not very much. Your going to have to stick with a 302 and get a good bottom end...