A 3" chop is a good choice, but there are a lot of issues to look at. Like how tall are you, what is a comfortable sitting position for you in the car, How does that work with your planned chop?? When you are driving the car, you want to be as comfortable as possible or you're not going to want to dirve it, especially any long distances. Once you figured out those things, then you will know just how much you want to lower the lid by.

My 34 sedan has a 4" chop, and I am 6'1". To comfortably see the road out of my windshield, which is just 8" tall now, I have to lay the back of my seat down on at least a 45 degree angle. You can get used to driving that way, but it ain't comfortable and sooner or later your back and legs will let you know it.

So do yourself a huge favor, test everything before the chop, because afterwards it will be too late.

Good luck with your project.