If you're getting the car for free.. why not!

btw.. where do you live?? Up here in the toronto area, the engine would cost you anywhere between $1400 (just for an engine with no harness) to $3000 CDN or more depending on the condition of the engine and what year it is.
Another option you would have is to go for a 20V Silver or blacktop 4AGE might cost you a bit more.. but they're worth it.. specially the blacktops. only thing is they're setup to run on high octane fuel. Sunoco Ultra94 might not even do the job.
There was a 94 corolla (I think) running around town with a 20V silvertop 4AGE, so you know you can do it to your car.
good luck man!