For that kind of money, I'd be leary. With all the weight it is going to support, I would rather see what I am getting. Besides, what you save in cost will most likely be spent on shipping.
Also, if you are going to support a straight 6, you might want to make sure that it is long enough to remain stable. What works fine for a small block V8, might not be ideal for a longer, maybe even heavier straight 6.
Just my opinion.
John
