Ring Seating on Break-in... How long?

LaCxefo

Ok, so let me start by saying I am not trying to start a debate on how to properly break-in an engine. I've searched and read everything I could find on google and this forum and have seen the direction it usually goes.

I just got my Z 4 days ago, and unfortunately had to drive it home from the dealership which is 250 miles of straight level highway from my town. Now I know that people on both sides of the fence (the drive it like you stole it, and those who abide by the manual) can agree on a few things that are proven. 1) don't keep constant rpm 2) keep the engine under load in lower gears to get the rings to wear evenly.

When driving it home, there wasn't much I could do to keep the engine under constant load, and the rpms only varied maybe 10k up and down in 6th gear for the most part. Since it's been home I've been trying to still keep it at a reasonable rpm, but get a good manifold pressure by putting some *** in it. And if I find myself on the highway, I shift and accelerate when possible.

My question is: I am at 550 miles now, are my rings still in the seating process and is it too late to change any "babying" that I have done thus far? Or does this process usually take place within like the first 50 miles? Just looking for opinions or some info I may have missed in my searching. I am a little paranoid after reading so many conflicting arguments after already driving 250 miles home before reading about any of it. Thanks in advance.