Buy stock replacement oil pan,pickup.
Mancini have pan packages...or reuse stock..and buy only the pickup.
Stock valve covers.
I've found intake manifolds on here from stock '66 273 4brl @$60 bucks to $250 for a strip dominator.. headers 150 bucks..
Used carb ,like a 600 edelbrock..$100-200
Cam n lifters around $300,don't skimp there. Buy bearings off ebay, $60 for a set of mains &rods. Get the right gasket kit, the one you need is about $70..the one with the extra garbage is $100 or so . Summit time set $50-80, springs $65, new stock exhaust/intake valves $100, pistons $110-$400, rings $30-60, oil pump $45,machine work $1200..
Possibles-reuse dampener, covers, exhaust manifolds and skip headers..jegs mandrel bent exhaust kit w/mufflers, stock fuel pump is fine, reuse trans lines, torque converter, trans overhaul. Recurve stock distributor. Water pump. Some things you can reuse and need to be new just for sake of being new.
5k? maybe that, if that.
You collect the parts by being patient and finding deals.