Good deal or not (WIW)

I think it's a good deal for the price.
Why is the guy selling it if it's such a good engine?
A leakdown test will tell you if there is any mechanical problems with the engine, it's better than a compression test. Do both if you can.
Ask to take the car for a drive, that will tell you if it has any power and what to expect.
Check the oil pressure with a good mechanical gauge, and if all checks out within reason, buy it!
$350 for a good running engine isn't very much at all.......
Even if it checks out o.k. but not perfect, i still think it's a good deal.