225 Slant needs a good idle. what rpms are you spinning?

What the book says and what your vehicle likes are 2 different things. I can dial mine down to below 300 in park and it will still run until I put it in gear, dies, to slow to run. The only real benefit is that you'll be saving gas and that's about it, if your oil and volts are happy at that idle, then so be it.