Just for laughs 150.00$ 1967 383

if you got a battery charger, you could lift the rust via electrolysis. dunk block in said stock tank, put in 2 cups of washing soda (not baking soda) and fill to top of block. clip battery charger - to block and + to a few sticks of rebar at the corners. Let it sit overnight, skimming off the crud that floats to the surface, check and repeat. Works great. Its line of sight so some may need to be repositioned.