Is this a fair trade for my s13?

yeah well, you're also being stupid

you cant judge the value of a car without fucking seeing it... visually. and visually, i mean inspecting the entire car from the brakes, tires, engine, oils, etc... thats why people pay shops for inspections, in order to achieve a fair value for the car. as a rough start, you use blue book and go from there.

as for your heap, well come to your own conclusions.. take all the time and money you decided to light on fire installing that hillbilly motor setup and go from there.

im not even trying to be a dick here, im just saying... you're asking too much from others when you should be doing the legwork here.