If it was me I would sell it as is on craigslist or something along those line.. If you scrap it/ salvage it your prolly gonna get $500 maximum. Sell it to someone on cl with it known it has engine issues, but also post it's clean, if the trans is in good shape, has new tires etc. you could probably get 1000-1500 for it to someone who fixes cars and resales em.. I doubt anywhere will give decent trade in anyway.
1990 prostar 190, 351, powerslot 1.5:1, tinted windows