Should I Buy the following and piss off the wife??

I think I will go ahead and get the intake as she would see it being used really soon. Maybe a nice dinner and musical would put me into the good books. Then hit her up 2 days later with, "you know that guy who sold me that intake super cheap? Well, he has some other parts (heads) that I need and it is an even better deal." And try to let her know what these cost to order and sell her on the fact that the heads are new. And that she knew what she was getting into before she said yes.....

I don't think I should have to hide anything from her> She might get mad, but she shouldn't if I am open and honest.

Last resort...... give her some money for her to blow.